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PARALLELISM    OF  THE  SOILS  DEVELOPED  ON 
THE   GRAY    DRIFTS    OF    MINNESOTA 


UC-NRLF 


B   ^   SE3   b70 


A  THESIS  SUBMITTED  TO  THE  FACULTY    OF  THE  GRADUATE 
SCHOOL  OF  THE  UNIVERSITY   OF   MINNESOTA 


BY 


i 


CLAYTON  ORD  'JIOST,   B.  Sc  ,  M.  A. 


iT-rx 


IN    PARTIAL  FULFILLMENT  OF  THE  REQUIREMENTS  FOR    THE 
DEGREE  OF   DOCTOR  OF   PHILOSOPHY 


JUNE    1918 


''I 

m 


PARALLELISM    OF  THE  SOILS   DEVELOPED  ON 
THE   GRAY    DRIFTS    OF    MINNESOTA 


A    THESIS  SUBMITTED  TO  THE  FACULTY    OF   THE   GRADUATE 
SCHOOL  OF  THE   UNIVERSITY   OF   MINNESOTA 


BY 


CLAYTON  ORD,  HOST,    B.  Sc  ,  M.  A.     i    ' 


IN    PARTIAL   FULFILLMENT   OF   THE    REQUIREMENTS    FOR    THE 
DEGREE  OF   DOCTOR  OF   PHILOSOPHY 


JUNE     1918 


3o^ 


-/ 


ACKNOWLEDGEMENTS. 

The  investigation  reported  in  this  thesis  was  undertaken  at  the 
suggestion  of  Dr.  F.  J.  Alway,  to  whom  the  author  is  indebted  for 
advice  and  assistance  during  its  progress.  Acknowledgement  is  also 
made  to  Mr.  W.  M.  Shaw,  who  assisted  in  part  of  the  analytical  work. 

C.  O.  R. 
University  of  Minnesota, 
Division  of  Soils. 
May  1,  1918. 


EXcnArsoK 


St 

« 


TAIU.E   OF   CONTENTS. 

Page. 
Introduction — 

Soil    formation 5 

Glacial  histon-  of  Minnesota 8 

Advantages  offered  hy  area  selected 10 

Soil  types  studied 11 

Previous  comparisons 14 

Studies  in   Illinois 14 

Studies  in   Iowa 16 

Studies   in    Minnesota 17 

FiKLD  Work — 

Selection  of  fields 18 

Method  of  sampling- V) 

MXPKRI  MENTAL 

A.  Relative  fineness  of  texture 20 

1.  Proportion  of  coarse  fragments 20 

2.  Texture  of  fine-earth 26 

B.  Lime  Supply 31 

1.  Carbonates    31 

2.  Reaction  with  litmus 34 

3.  Reaction  by  the  Truog  method 35 

4.  Coloration  of  ammonia  solution 37 

5.  Comparison    of    indications    obtaii  led    by    different 

methods    39 

6.  Relation  of  calcareousness  to  texture 40 

7.  Relation  of  carcareousness  to  age  of  drift 40 

C.  Inorganic  Constituents — 

1.  Methods  of  analvsis 41 

2.  Silica  ' 44 

3.  Iron   45 

4.  Alumina    45 

5.  Titanium 46 

6.  Lime    46 

7.  Magnesia    48 

8.  Phosphoric  acid 49 

9.  Potash 52 

10.  Soda    52 

D.  Organic  Constituents — 

1.  Volatile  matter 53 

2.  Organic  carbon 54 

3.  Nitrogen 54 

E.  Color    58 

Classification  of  Rice  County  types  according  to  thi  Russian  system  62 

Summary    63 

Literature  Cited 66 


576448 


INTRODUCTION. 

Soil  is  to  be  defined  as  the  superficial  wealliered  layer  of  the  solin 
earth-crust,  the  last  including  not  only  the  solid  rocks  but  also  unconsol- 
idated formations  such  as  loess,  dune-sands,  and  glacial  deposits. 
Soils  are  variously  defined,  according-  to  whether  the  particular  writer 
is  viewing  them  as  the  hal)it.it  of  plants — the  botanical  viewpoint,  or  as 
simply  the  superficial  geological  formation — the  geological  viewpoint. 
Accordingly  the  depth  of  the  superficial  layer  included  under  the  gen- 
eral designation  "soil"  varies  from  writer  to  writer,  the  geologist  often 
taking  for  this  a  higher  value  than  the  botanist.  The  latter  will  con- 
sider it  to  extend  at  least  as  deep  as  plant  roots  penetrate,  and  the  form- 
er as  deep  as  the  composition  of  the  parent  rock  may  have  been  affected 
by  percolating  water,  aided  more  or  less  by  organisms  or  their 
products. 

As  the  common  farm  crops  in  southern  .Minnesota  derive  not 
only  their  mineral  constituents  but  also  their  supply  of  water  chiefly 
from  the  first  three  feet  and  almost  exclusively  from  within  the  fir.st 
five  feet,  we  scarcely  need  to  consider  the  portion  below  the  fifth  foot. 
As  most  of  the  crops  draw  more  or  less  upon  the  third  foot  for  these, 
and  hence  the  whole  of  the  first  three  foot  section  is  to  be  considered 
as  well  within  the  root  zone  so  that  a  study  of  the  soil  should  include 
sections  to  at  least  this  depth. 

The  great  majority  of  Minnesota  soils  are  glacial  in  origin  and. 
for  the  most  part,  developed  upon  the  vinassorted  glacial  till  left  behind 
by  five  separate  and  distinct  ice  sheets.  Under  these  circumstances 
one  of  the  first  questions  occurring  to  a  soil  investigator  in  this  state  is 
as  to  what  relation,  if  any,  exists  between  the  character  of  the  soils 
upon  the  various  glaciations  and  the  age  of  the  latter.  The  object 
of  the  investigation  reported  in  this  thesis  was  to  answer  the  question  in 
part. 

Soil  Formation. 

The  surface  three  feet  or  so  of  a  freshly  exposed  lake-bed, 
recently  formed  sand-dune,  till-plain  or  terminal  moraine  just  exposed 
by  a  retreating  glacier,  is  not  to  be  considered  as  soil  but  as  the  parent 
rock  upon  which  soils  may  be  developed  by  the  combined  agencies  of 
living  organisms  and  the  products  resulting  on  the  death  of  these,  and 
of  percolating  or  descending  waters,  these  carrying  carbonic  acid,  solu- 
ble salts  and  organic  compounds. 

The  form  of  alteration  in  the  parent  rock  that  will  be  induced  by 
the  soil- forming  agencies  will  de])end  upon  the  vegetative  covering,  the 
temperature,  the  precipitation,  the  rate  of  evaporation,  and  the  level 


of  the  ground  water,  as  well  as  upon  the  perviousness  to  descending 
water  of  the  parent  rock  and  the  water  retaining  capacity  of  its  super- 
ficial portion.  The  vegetative  covering,  in  its  turn,  is  largely  determin- 
ed by  the  character  of  the  parent  rock  or  of  the  soil  developed  upon  this, 
together  with  the  climate  of  the  locality.  Hence,  the  properties  of  the 
parent  rock  and  the  climate  of  the  region  in  which  it  happens  to  be 
exposed  will  together  determine  the  relative  importance  of  the  various 
soil-forming  agencies  and  accordingly,  the  character  of  the  resulting 
soil. 

In  general  the  character  of  a  soil  is  much  more  dependent  upon  the 
climate  of  the  region  in  which  it  is  found  than  upon  the  nature  of  the 
parent  rock,  or  upon  the  manner  of  its  formation.  Thus  a  granite, 
a  wind-laid  silt  loam  and  a  lacustral  clay  may  weather  to  produce  soils 
of  a  very  similiar  character  when  all  three  have  been  exposed  to  the 
same  climate  for  a  sufficient  length  of  time,  while  soils  of  an  entirely 
different  character  might  arise  on  these  same  formations  under  other 
climatic  conditions  (2,  p.  199). 

Accordingly,  as  the  climate  of  the  earth  shows  a  zonal  distribution, 
the  soil,  unlike  any  other  geological  formation,  also  shows  a  zonal  dis- 
tribution, similar  zones  appearing  in  regular  order  on  the  different  con- 
tinents and  in  both  hemispheres  (15,  map  2)  as  we  pass  from  the 
equator  poleward,  or,  in  a  tropic  or  temperate  region,  ascend  a  high 
mountain  (16,  p.  343).  Thus,  desert  soils  in  the  United  States  resemble 
desert  soils  in  Africa  or  Asia  and  the  black  prairie  soils  of  the  United 
States  resemble  the  Chernozem  of  European  Russia  and  Siberia  (16, 
p.  286;  2,  p.  231 ;  4,  p.  423)  and  the  pampas  soils  of  Argentina  (16.  p. 
44  and  114).  If  one  but  knows  the  climate  of  a  region  the  general 
character  of  the  soils  can  be  predicted. 

Where  the  character  of  the  parent  rock,  its  chemical  composition 
or  its  physical  properties,  have  been  such  as  to  leave  upon  the  result- 
ing soil  an  impression  not  overshadowed  by  the  climate  the  soil  is,  ac- 
cording to  Glinka,  to  be  designated  Endodynamomorphic  but  otherwise 
as  Ektodynamomorphic  (16,  p.  35;  27,  p.  559).  It  is  with  the  latter 
group  of  soils  that  the  present  study  is  concerned  and  these  may  be 
divided  into  six  classes. 

/.  Soils  formed  zvhcre  the  mean  temperature  is  high  and  the  preci- 
pitation very  high  or  fairly  high. 

The  most  of  the  organic  material  decays  rapidly,  causing  a  low 
proportion  of  this  in  the  soil,  and  the  salts  resulting  from  the  decay 
and  the  weathering  of  the  silicates  are  completely  leached  out.  The 
silicic  acid  derived  from  the  weathering  of  silicates  and  alumino-sili- 
cates  is  leached  out  along  with  the  alkali  and  alkali  earth  metals,  leav- 
ing behind,  in  addition  to  the  quartz,  the  alumina,  ferric  oxide  and 
titanium  oxide. 

The  laterites  (title-colored  soils  10,  p.  440)  of  the  moister,  and  the 
Red  Earths  of  the  drier  portions  of  the  tropics  belong  to  this  class. 


The  yellow  soils  of  southern  France  {21 ,  p.  600)  and  of  Japan  are  re- 
lated to  the  Red  Earths,  the  removal  of  the  silica  being  charcteristic 
of  only  the  later  stages  as  in  the  laterites.  In  the  latter,  in  various 
places,  the  concentration  has  proceeded  so  far  as  to  make  such  soils 
serve  as  a  source  of  metallic  iron,  really  as  a  low  grade  ore. 

//.  Soils  xvhcrc  the  precipitation  is  lower  and  the  temperature 
much  loxver  than  in  the  preceding,  as  over  northwestern  and  western 
Europe  and  in  the  United  States  east  of  the  Mississippi  river. 

The  soluble  salts  are  leached  out,  the  carbonates  removed  from  the 
upper  layer,  and  a  certain  amount  of  iron  transported  from  tlie  upper 
to  the  lower  layers  (^27,  p.  554).  Only  part  of  the  organic  matter  is 
lost  rapidly,  thus  permitting  the  accumulation  of  a  comparatively  large 
amount  in  the  upper  layers.  In  the  colder,  moister  regions  there  result 
podsols,  characterized  by  a  whitish  or  gray  horizon  near  the  surface 
with  a  concentration  of  iron  at  a  greater  depth  and  a  markedly  acid 
reaction.  Along  with  the  iron,  manganese,  calcium,  magnesium,  potas- 
sium and  sodium  more  or  less  phosphoric  acid  is  leached  out  of  the 
upper  layers  and  redeposited  with  the  iron  and  manganese  at  a  lower 
horizon  (15,  p.  78).  Where  the  temperature  is  higher,  either  degrad- 
ed chernozems,  brown  earths  or  gray  forest  soils  develop.  These 
show  less  translocation  of  iron  and  little  or  none  of  phosphoric  acid. 
Both  the  true  podsols  and  the  brown  or  gray  forest  soils  develop  under 
forest  conditions. 

///.  Soils  formed  7cliere  the  precipitation,  evaporation,  tempera- 
ture and  topographical  conditions  cause  a  grassla)id  I'egetation  to  hold 
its  own  against  the  forest. 


The  abundant  growth  of  grasses  exhausts  tlie  soil  moisture  supply 
and  causes  a  delayed  decomposition  of  their  remains  with  the  result 
that  the  organic  matter  content  of  the  soil  is  high.  The  plants,  being 
chiefly  annuals,  biennials,  or  short-lived  perennials,  frequently  con- 
tribute both  root  and  stem,  as  well  as  leaf,  to  the  soil  forming  agencies 
and  the  organic  matter  is  increased  as  deeply  as  the  roots  penetrate. 
Alkali  salts  are  removed  and  the  carbonates  largely  leached  out  of  the 
upper  layers  are  deposited,  for  the  most  part,  in  the  base  of  the  zone 
of  maximum  root  pentration.  Gypsum  is  redeposited  at  a  still  lower 
level,  if  at  all.  Alkali  salts  and  carbonates  formed  by  the  action  of  car- 
bon dioxide  upon  the  silicates  behave  like  the  original  soluble  salts  and 
carbonates,  while  the  resulting  silicic  acid  remains  in  the  upper  layers 
(2,  p.  315).  The  class  includes  the  Black  Earths  or  Chernozems  of 
Russia  and  the  black  and  part  of  the  brown  prairie  soils  of  the  Ignited 
States  and  Canada  (21,  p.  207  and  338). 


IV.  Soils  of  the  semi-arid  or  arid  regions  with  a  short  grass  or 
desert  vegetation. 

The  content  of  organic  matter  is  lower  than  in  the  preceding 
group.  Little  or  no  percolation  occurs.  The  movement  of  mineral 
constituents  is  confined  to  a  concentration  of  carbonates  and  soluble 
salts  just  beyond  or  near  the  root  tips  in  the  drier  regions  and  to  the 
removal  of  only  the  soluble  salts  in  the  moister.  This  condition  is 
found  on  the  Great  Plains  of  the  United  States  and  Canada  and  on  the 
Steppes  of  Russia  (16,  p.  132). 

V.  Soils  formed  under  excess  of  moisture,  the  upper  soil  horizon 
being  saturated  with  water  the  most  of  the  time. 

Organic  matter  being  unable  to  decay  accumulates,  iron  is  present 
largely  as  ferrous  salts,  and  pyrites  is  formed.  Where  there  is  no 
outlet  for  the  water  evaporation  will  cause  an  accumulation  of  gypsum 
and  carbonates  near  the  surface  if  these  are  present  in  surrounding 
higher-lying  soils.  Peat,  muck  and  marsh-meadow  soils  belong  to  this 
group. 

VI.  Alkali  soils. 

These  form  in  both  the  third  and  fourth  zones  in  places  where 
water  accumulates  periodically  and  then  escapes  by  evaporation,  there 
being  little  or  no  loss  by  seepage  or  run-oflf  (18,  p.  103),  or  where 
water  rises  from  a  water  table  close  to  the  surface  and  evaporates  so 
rapidly  that  the  percolation  following  rains  does  not  counter-balance 
the  ascent  of  soluble  salts. 

Glacial  History  of  Minnesota. 

The  whole  of  the  state  of  Minnesota,  with  the  exception  of  a  very 
small  area  in  the  extreme  southeastern  corner,  has,  at  one  time  or 
another  been  glaciated  (23  p.  16),  the  mantle  of  glacial  material  left 
behind  constituting  the  parent  rock  of  most  of  its  soils.  The  study 
of  the  deposits  left  behind  by  the  receding  ice  has  shown  that  they 
are  the  result  of  successive  glaciations,  some  of  the  ice  sheets  hav- 
ing radiated  from  centers  east  of  James  Bay  and  being  designated 
the  Labradorian,  and  the  others  from  north  or  northwest  of  Minnesota 
and  being  referred  to  as  the  Keewatin.  While  some  of  the  ice  sheets 
from  different  centers  may  have  been  contemporaneous,  or  the  one  may 
have  followed  almost  immediately  after  the  other,  in  most  cases  each  of 
the  advances  of  ice  after  the  first  was  so  widely  separated  in  time  from 
its  immediate  predecessor  that  under  the  milder  climate  prevailing  the 
earlier  deposit  had  had  soils  developed  upon  it  and  drainage  channels 
fully  formed.  The  succeeding  invasion  then  planed  oflf  the  hilltops, 
filled  up  the  valleys  and  buried  the  remaining  portion  of  the  earlier 
drift  sheet.  In  those  cases  v.'here  one  of  the  later  ice  sheets  did  not 
extend  as  far  as  the  earlier,  there  is  offered  an  opportunity  for  a  com- 
parison of  the  soils  formed  on  the  two. 


The  drift  material  carried  into  Minnesota  and  left  brhind  I)y  the 
melting:  ice  was  picked  up  between  the  center  from  which  the  glacier 
radiated  and  the  northern  border  as  well  as  along-  its  course  across 
the  state.  In  the  case  of  the  later  ice  sheets  glacial  debris  left  by  the 
earlier  invasions  was  to  a  greater  or  less  extent  incorporated  in  the 
mass  of  fresh  material  l)rought  by  the  advancing  ice.  a  factor  which 
complicates  such  a  comparison  as  that  mentioned  above. 

From  eleven  to  thirteen  successive  stages  of  the  glacial  period  are 
generally  recognized  as  applving  to  the  United  States  (13,  p.  383). 
These  are  as  follows,  the  most  recent  (XIII)  being  given  first  and  the 
oldest  last  (I). 

XIII — The  Champlain  sub-stage  (marine). 
XII — The  glacio-lacustrine  sub-stage. 
XI — The  later  Wisconsin,  the  sixth  advance. 
X — The  fifth  interval  of  deglaciation,  as  yet  unnamed. 
IX — The  Earlier  Wisconsin,  the  fifth  invasion. 
VIII — The  Peorian,  the  fourth  interglacial  interval. 
VII — The  lowan,  the  fourth  invasion. 
VI — The  Sangamon,  the  third  interglacial  interval. 

V — The  Illinoian,  the  third  invasion 
IV — The  Yarmouth,  or  Buchanan,  the  second  interglacial  inter- 
val. 
Ill — The  Kansan,  or  second  invasion  now  recognized. 
II — The  Aftonian,  the  first  known  interglacial  interval. 
I — The  Sub-Aftonian,  or  Jerseyan,  the  earliest  known  inva- 
sion. 

There  is  some  doubt  as  to  the  existence  of  the  lowan.  The  late 
FVofessor  Calvin  and  members  of  the  Iowa  Geological  Survey  have 
regarded  this  as  a  distinct  stage  of  glaciation  but  little  older  than  the 
Wisconsin.  Leverett  (22,  p.  282)  was  at  first  inclined  to  regard  this 
as  possibly  of  Illinoian  age  but  has  later  come  to  consider  it  as  part  of 
the  Kansan.  In  this  case  the  Sangamon  and  the  Peorian  interglacial 
intervals  would  be  identical.  In  the  present  thesis  the  views  of  Lev- 
erett are  accepted. 

• 

Of  the  six  glacial  invasions  five  crossed  what  are  now  the  borders 
of  this  state  (22,  p.  248  ff ;  13,  p.  382  flf).  The  first  of  these  was  the 
Pre-Kansan,  or  Nebraskan,  which  corresponds  to  the  Sub-Aftonian. 
This  radiated  from  the  Keewatin  field  and  covered  the  greater  part  of 
the  state  but  none  of  the  drift  is  now  naturally  exposed  in  Minnesota, 
it  having  been  entirely  buried  by  the  following  invasions  and  being 
now  encountered  only  in  the  deeper  wells. 

The  second  ice  sheet  to  reach  Minnesota,  the  Kansan  (Fig.  1),  also 
radiated  from  the  Keewatin  field,  covering  every  part  of  the  state 
either  previously  or  subsequently  glaciated.  The  mantle  left  behind  is 
designated  as  the  Old  Gray  Drift  and  is  still  exposed  in  parts  of  Dakota, 


10 

Rice,  Dodge,  Olmstead,  Goodhue,  Mower.  Fillmore,  Pipestone  and 
Rock  counties.  Its  presence  in  the  last  two  counties  named  was  not 
recognized  by  glacial  geologists  until  after  the  field  work  in  this  study 
had  been  completed. 

The  Illinoian,  the  third  to  reach  the  state,  covered  only  a  small  area 
in  Washington  count}-  and  the  greater  part  of  Dakota  county.  It  came 
from  a  Labradorian  center  and  over-rode  the  Kansan.  The  till  left  be- 
hind is  designated  the  Old  Red  Drift. 

The  fourth  advance  of  the  ice  into  Minnesota,  the  Early  Wiscon- 
sin, approached  from  the  northeast  and  covered  a  considerable  area 
to  the  west  and  southwest  of  Lake  Superior  (Fig.  1)  and  left  a  mantle 
of  till  known  as  the  Young  Red  Drift.  These  two  ice  sheets  crossing 
highly  ferruginous  rock  formations  gathered  up  portions  of  these  and, 
consequently,  the  soils  developed  upon  the  till  show  a  distinctly  red 
color. 

The  fifth  ice  sheet,  the  Late  Wisconsin,  which  brought  the  Late 
Gray  Drift,  radiated  from  a  Keewatin  center  to  the  north  or  slightly  to 
the  northwest  of  Minnesota  and  covered  a  much  larger  portion  of  the 
state  (Fig.  1)  than  either  of  its  immediate  predecessors.  This  younger 
formation  in  contrast  to  the  Old  Gray  Drift  is  characterized  by  numer- 
ous lakes  and  poorly  drained  areas  such  as  the  deposits  older  than  the 
Young  Red  Drift  do  not  possess.  Fully  developed  drainage  lines  are 
to  be  found  only  where  they  were  formed  by  the  out-rushing  water 
from  the  melting  ice. 

In  addition  to  the  Des  Moines  Lobe  of  the  Late  Wisconsin  there 
was  a  contemporaneous  Superior  Lobe  in  which  the  ice  advancing 
up  to  the  bed  of  Lake  Superior  spread  to  the  north,  northeast,  east 
and  southeast.  The  till,  almost  free  of  limestone,  was  derived  from 
crystalline  rocks  and,  like  the  Illinoian  and  early  Wisconsin  in  Min- 
nesota, has  a  red  color. 

Each  period  of  glaciation  was  separated  from  the  succeeding  one 
by  an  interglacial  interval  which,  in  some  cases,  was  very  long,  prob- 
ably much  longer  than  the  time  which  has  elapsed  since  the  Late 
Wisconsin.  The  successive  stages  appear  to  have  become  shorter,  the 
earlier  being  much  longer  than  the  later  ones  (13,  p.  382). 


Advantages  Offered  by  Area  Selected. 

Rice  county  in  southeastern  Minnesota  ottered  the  best  site  in 
the  State  for  a  study  of  the  influence  of  the  age  of  a  glaciation  upon 
the  character  of  the  soils.  The  earliest  glaciation  from  which  any 
till  remains  uncovered  by  later  deposits,  the  Kansan,  covered  the  whole 
of  what  is  now  included  in  the  county  boundaries  while  the  most  recent 
of  all  the  glaciations.  the  Late  Wisconsin,  covered  only  the  western 
two-thirds  and  no  intenening  ice  sheets  had  entered  the  area,  except 
possibly  the  Earh   Wisconsin  at  the  very  edge  on  the  north   (Fig.  1) 


Fig.  1. — Map  of  Minnesota  showing  surface  formations.     (By  Leverett,  F., 
and  Sardeson.  F.  W.,  Minu.  Gcol.  Sttnry  Bui.  No.  14,  p.  13.) 


'VcKi(5,' ^.^UisfrtlUjtjyy /of,  fp.rest  in  Minnesota.     Map  by 
ers7T/!('  "Phut  U'Wld,  Vol.  21,  No.  5,  /).  ///). 


Rosendahl  and  But- 


11 

A  long  period  of  time,  includiiiij  several  epochs  of  glaciation  as  well 
as  long  interglacial  periods,  in  which  floras  and  faunas  were  devel- 
oped, elapsed  between  the  two.  lioth  glaciers  radiated  from  Keewatin 
centers  and  accordingly  brought  along  with  them  similar  material,  the 
chief  characteristic  of  which  was  an  abundance  of  limestone  fragments. 
Thus  we  have  in  Rice  county,  side  by  side,  the  soils  developed  on 
the  oldest  exposed  and  those  on  the  very  youngest  of  the  glacial  forma- 
tions, both,  since  the  melting  of  the  last  ice-sheet,  subjected  to  the 
same  climatic  influences  and  ex])osed  to  the  same  soil  forming  agencies. 

For  such  a  study  it  is  highly  desirable  to  be  able  to  compare  soils 
formed  luider  dififerent  vegetation  conditions,  e.  g.,  forest  soils  on  the 
earlier  drift  with  forest  soils  on  the  later,  the  natural  grassland  soils 
on  the  former  with  natural  grassland  soils  on  the  latter.  Rice  is  the 
only  county  in  which  this  is  possible,  the  other  counties  in  which  the 
tw'o  selected  drifts  occur  side  by  side  being  south  of  the  limit  of  the 
forest  (Fig.  2). 

Further,  for  Rice  county  there  was  available  a  detailed  soil  sur- 
vey by  the  United  States  Bureau  of  Soils  made  in  1 WJ  and  i)ublished  in 
1911  (11)  while  Leverett,  who  was  completing  a  detailed  study  of  the 
glacial  history  of  the  state,  kindly  made  a  detailed  demarcation 
of  the  eastern  boundary  of  the  Late  Wisconsin  glaciation  within  the 
county,  this  having  not  yet  been  reported  in  printed  form. 

In  the  survey  by  the  Bureau  of  Soils  the  two  drifts  exposed  on 
the  surface  are  mentioned  (11,  p.  21-23),  Leverett  having  personallv 
indicated  the  boundaries  to  the  surveyors  but  no  attempt  was  made  by 
the  latter  to  difTerentiate  types  in  respect  to  the  two  drifts  although  it  is 
stated  (11,  p.  21)  that  "the  limestone  from  which  much  of  this  drift 
(Kansan)  is  derived,  has  long  since  given  way  to  the  agencies  of 
weathering  and  only  the  more  resistant  rocks  are  left,  whereas  in  the 
Wisconsin  drift  limestone  and  shales  in  addition  to  numerous  cherty 
and  crystalline  rocks  are  very  common."  Fourteen  types  of  soil  were 
mapped,  of  which  three  of  the  most  extensive,  viz.,  Carrington  silt 
loam,  Fargo  silt  loam,  and  Carrington  loam,  have  representative  areas 
on  both  drifts. 

Thus  Rice  Count}-  offered  an  exceptional  op]Jortunity  not  only  for 
the  study  of  the  differences  in  the  mechanical,  chemical  and  petrograh- 
ical  composition  resulting  from  the  difference  in  age  of  the  drift  and 
the  consequent  longer-continued  leaching  on  the  one  than  on  the  other, 
but  also  to  determine  whether  soil  classification  as  applied  by  the  United 
States  Bureau  of  Soils  properl)'  recognizes  differences  between  soils  on 
different  drifts. 

Soil  Types  Studied. 
Only  four  soil  types  are  dealt  with  in  the  present  study,  viz.. 
Carrington  silt  loam,  Fargo  silt  loam.  Carrington  loam  and  ^Marshall 
silt  loam.  A  soil  type,  as  the  term  is  employed  by  the  U.  S.  Bureau  of 
Soils  (12,  p.  11),  is  the  unit  of  classification  and  is  defined  as  including 
all  soils  that  are  alike  agriculturally,  or  as  nearly  alike  as  it  is  possible 
to  detemiine  bv  field  methods. 


12 

The  type  name  results  from  combining  the  class  name  of  the  sur- 
face material  with  the  series  name  (Fargo,  Carrington,  etc.).  The 
class  (loam,  silt  loam,  clay,  etc.)  is  determined  by  the  texture  of  the 
surface  soil,  the  portion  encountered  by  tillage  implements,  as  decided 
upon  in  the  field  by  the  experienced  surveyor  and  later  confinned  in  the 
laboratory  by  mechanical  analysis  of  typical  samples.  The  series  name 
as  it  serves  as  a  key  to  all  the  important  properties  of  the  type  except 
the  texture  of  the  surface  stratum,  is  based  upon  the  color  and  content 
of  organic  matter  in  both  surface  soil  and  subsoil,  the  subsoil  profile, 
the  topography,  the  origin  and  the  mode  of  formation  as  well  as  any 
prominent  chemical  dififerences-  insofar  as  they  are  likely  to  affect 
agricultural  practice.  A  series  includes  all  the  types  that  differ  from 
one  another  only  in  the  texture  of  the  surface  stratum.  The  total 
nimiber  of  series  in  the  United  States  so  far  recognized  by  the  Bureau 
of  Soils  amounts  to  abouli  600  and  the  tvpes  to  a  little  in  excess  of 
1.650. 

The  soils  of  the  Carrington  series  are  derived  from  the  weather- 
ing of  the  glacial  drift.  (I^arrington  loam  occupies  the  rolling  up- 
lands, is  generally  well  drained  and  originally  was  nearly  all  covered 
with  deciduous  forest — the  Big  Woods.  Carrington  silt  loam  is  con- 
fined almost  entirely  to  those  higher-lying  portions  of  the  county  which 
were  originally  covered  by  prairie.  On  the  Wisconsin  the  drainage  is 
good,  while  on  the  Kansan  it  is  much  poorer  than  that  of  the  Carring- 
ton loam.     Boulders,  some  very  large,  occur  in  small  numbers  on  both. 

The  Carrington  loam  is  described  (11,  p.  22-23)  as  "a  brownish 
black  or  yellowish  brown  silty  loam,  12  to  24  inches  deep,  grading 
into  a  heavy  yellow  clay,  which  usually  exceeds  a  depth  of  15  feet. 
The  texture  of  the  surface  soil  is  for  the  most  part  uniform,  but  the 
color  and  depth  are  variable.  A  depth  of  15  inches  is  more  typical  than 
either  of  the  extremes.  There  are  few  stone  fragments  in  the  material 
to  a  depth  of  three  feet,  though  these  increase  in  quantity  with  depth." 

The  Carrington  silt  loam  (11,  p.  26)  is  "a.  grayish-black  or  black 
heavy  silty  loam,  with  a  depth  of  15  inches,  grading  into  a  drab  or 
brownish  silty  clay  which  at  about  24  inches  is  underlain  by  dark  yel- 
low clay.  The  soil  is  generally  unifomi  in  texture  and  has  a  high 
content  of  organic  matter." 

The  Fargo  silt  loam  is  described  (11,  p.  32)  as  "a  black  clay  or 
silty  clay  loam  from  10  to  15  inches  deep,  grading  into  a  dull  colored 
clay  which  at  20  to  30  inches  changes  to  a  yellow  and  gray  plastic  clay. 
Beneath  this  there  usually  occurs  a  thin  layer  of  sand,  sandy  clay  or 
gravel.  In  the  southeast  corner  of  the  county  the  Fargo  silt  loam  occu- 
pies a  part  of  the  original  plain  of  the  Kansan  drift,  but  elsewhere  it  is 
a  bottom-land  type.  The  topography  is  generally  level  but  is  character- 
ized by  very  gentle  slopes  as  it  approaches  sloughs  and  streams.  The 
areas  are  generally  poorly  drained  and  water  is  often  found  within 
the  3-foot  section  in  the  bottoms." 

"The  soil  material  along  the  sloughs  has  been  washed  from  the 


l.?^-. 


%^^^-^: 


I,\K(.I-;      ls(  I.ATEI)      l')(,ri.liKk>      UN     THK      K.WS.W. 

1.  Pegmatite.    X<irtli  <it    Xcrstraini. 

2.  Ciranitf.  mar   Field   III   on  (arriii!  ii  m   l.ojm. 


PI^ATK    II 


Ir.LusTKATixr.  TdPiicKAi'H V  OX  Carrixgtox  Sii.t  Loam. 


1.  I'ield  V — on  tlio  Kansaii. 

2.  I'^ield  \' — on  the  Late  Wisconsin. 


13 

higher  slopes  and  has  accuinulated  faster  than  the  sluggish  streams  can 
remove  it.  Some  of  the  type,  however,  is  lacustrine  in  origin,  having 
been  deposited  in  shallow  basins  or  ponds.  A  very  small  part  of  it  can 
be  attributed  to  stream  and  river  overllows."  ( )riginally  it  was  almost 
exclusively  grass-laml. 

Marshall  loam,  designated  Marsliall  sill  ktani  in  counties  more  re- 
cently surveyed,  is  derived  from  the  weathering  of  loess  deposits 
(11,  p.  35).  The  surface  soil  is  a  yellowish  brown  or  brown  silty 
loam  to  6  or  12  inches,  under  which  is  a  compact  yellow  silty  loam 
and  under  this,  at  a  depth  varying  from  24  to  36  inches,  a  loose 
incoherent  silty  material  lighter  in  color.  The  loess  deposit  varies  from 
a  few  inches  to  1.^  feet  in  thickness  and  iii  this  county  is  underlain 
by  glacial  material. 

The  mechanical  composition  of  typical  samples  from  the  county 
reported  by  Burke  and  Kolbe  (11)  is  given  in  table  1.  These  show 
the  Carrington  loam  to  be  coarser  in  texture  than  the  three  silt  loams, 
having  considerably  less  of  particles  as  fine  or  finer  than  very  fine  sand 
and  accordingly  more  of  the  coarser  fractions.  The  finer  fractions 
of  the  silt  loams  constitute  from  81.6  to  94  per  cent  of  the  surface  soil 
and  from  68.9  to  91.4  per  cent  of  the  subsoil,  while  for  the  loam  they 
form  only  76.2  and  68.5  per  cent  for  soil  and  sul^soil,  respectively.  The 
mechanical  composition  of  the  subsoil  of  the  kargo  silt  loam  is  very 
similiar  to  that  of  the  Carrington  loam. 

Table  i. — Mechanical  composilion  of  typical  sainpL's  from  Rice  County,  as 
reported  by  Burke  and  Kolbe. 


Siratum 

Fine 
gravel 
per  cent 

Coarse 

sand 
per  cent 

Medium       Fine       Very  fine 

sand          sand           sand            Silt 
per  cent    per  cent    per  cent   per  cent 

Carrington  Loa:vi. 

Clay 
per  cent 

Con 

Moist 

r.y  B&Si 

formula 

iputed 
.  equiv. 
P.y  A&R2 
formula 

Soil    .... 
Subsoil    . 

0.7 
1.1 

4.0 

6.4 

5.1        13.8          9.9        49.0 
6.7        16.8        14.4        36.5 

Carrington  Silt  Loam. 

17.3 
17.6 

29.7 
27.4 

27.1 
24.5 

Soil    .... 
-Subsoil    . 

0.0 
.       0.0 

1.2 

2.3 

1.6          2.8        18.8        62.3 
2.2         3.8        30.9        39.7 

Fargo  Silt  Loam. 

12.9 
20.8 

27.7 
31.3 

27.1 
27.3 

Soil    .... 
Subsoil    . 

0.0 
.       1.9 

3.3 
6.2 

4.2          9.4         4.9        65.0 
7.0        15.6        10.1        39.8 

Marshall  Silt  I.X)AM. 

13.1 
19.0 

28.4 
29.5 

28.0 
26.5 

Soil    .... 

Subsoil    . 
Lower 
Subsoil    . 

0.1 
0.0 

0.0 

1.7 
1.5 

1.0 

4.6        12.1         10.6        50.5 
4.9        10.0        38.9        26.4 

5.0        13.3        25.0        42.4 

20.5 
17.9 

13.2 

33.2 

25.7 

24.1 

28.6 
24.3 

24.6 

1.  Briggs  and  Shantz. 

2.  Alway  and  Russell. 

The  great  amount  of  time  consumed  by  a  mechanical  analysis  pre- 


14 

vents  it  being  exclusively  employed  in  survey  work.  Certain  physical 
constants,  viz.,  the  hygroscopic  coefficient  and  the  moisture  equivalent, 
are  dependent  upon  the  mechanical  composition  and  express  in  a  single- 
valued  term  the  relative  fineness  of  texture  and  have  the  additional 
advantage  of  being  readily  determined.  Briggs  and  McLane  (6,  p. 
20-21)  and  Briggs  and  Shantz  (8,  p.  73)  have  proposed  the  formulas — 
Hygroscopic  coefficient=r0.0007  sand  -(-  0.082  silt  -f-  0.39  clay  and, 
Moisture  equivalent=:0.02  sands  -)- 0.22  silt  +  1-^5  clay.  Alway  and 
Rost  (4,  p.  10),  working  on  the  relation  of  the  hygroscopic  co-efficient 
of  loessial  soils  to  the  mechanical  composition,  have  pointed  out  that  no 
one  formula  for  such  a  physical  constant  wnll  do  for  all  soils  but  that 
as  an  approximation  for  the  loess  soils  that  they  were  dealing  with 
the  above  will  serve. 

Similarly  Alway  and  Russel  (5,  p.  842)  dealing  with  the  moisture 
equivalents  of  the  same  soils  have  developed  the  formula :  Moisture 
equivalent=0.14  sands  -J- 0.27  silt  -}- 0.53  clay.  The  moisture  equiva- 
lents as  calculated  by  these  two  formulas  are  shown  in  columns  9  and 
10  of  table  1.  The  results  obtained  by  the  two  formulas  are  ver}' 
similar. 


Previous  Comparisons. 

A  limited  amount  of  data  showing  the  relations  of  the  chemical 
composition  of  glacial  soils  to  the  age  of  the  drift  upon  which  they 
occur  is  already  available,  but  none  of  the  studies  were  made  under 
conditions  so  favorable  as  those  existing  in  Rice  county.  Hopkins  and 
Pettit  (20)  in  Illinois,  Brown  (9)  in  Iowa,  and  McMiller  (25)  in 
Minnesota  have  each  reported  a  study. 

Hopkins  and  Pettit's  study  was  based  upon  Leverett's  drift  survey 
of  Illinois  in  which  six  glaciations  had  been  mapped.  A  considerable 
number  of  samples  were  collected  from  three  depths  on  each,  0-7,  7-20, 
and  20-40  inches,  and  subjected  to  analysis  for  nitrogen,  carbon,  potas- 
sium and  phosphorus.  The  averages  for  the  dififerent  drift  sheets  are 
summarized  in  table  2. 

As  the  glacial  soils  of  Illinois  are  generally  covered  by  a  layer  of 
loess  from  3  to  10  feet  or  more  in  depth  (20  p.  193)  the  samples  were 
not  of  till  but  of  the  overlying  mantle,  and  the  age  of  the  latter  is  not 
necessarily  similar  to  that  of  the  former.  Hopkins  and  Pettit  appear 
to  have  assumed  that  after  each  glaciation  the  freshly  exposed  till 
became  quickly  covered  with  its  mantle  of  loess,  this  being  derived  from 
the  till  sheet,  a  portion  of  which  it  covered,  and  that  the  loess  deposited 
on  the  later  till  sheets  was  derived  chiefly  from  these  and  did  not  affect 
the  soils  on  the  earlier  glaciations.  There  appears  no  satisfactory'  evi- 
dence that  these  assumptions  are  justified  and  hence  it  is  doubtful  just 
what  importance  we  should  attach  to  their  data  in  connection  with  the 
question  of  the  relation  of  the  composition  of  a  glacial  soil  to  the  age  of 


15 


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ihe  drift  upon  which  it  has  been  develo])e(l.  It  should  be  ])ointed  out 
that  Hopkins  and  Pettit's  investigation  was  not  planned  to  answer  this 
question,  but  to  determine  the  general  character  of  Illinois  soils,  their 
data  being  reported  by  glaciations  arranged  in  order  of  age,  in  order  to 
bring  out  any  relation  existing  between  the  age  and  the  chemical  com- 
position. While  they  report  no  ])hysical  constants  the  omission  of 
these  is  not  very  serious,  as  the  soils  alluded  to  in  table  2  appear  to  all 
have  been  silt  loams  or  clay  loams  of  loessial  origin. 

The  composition  does  not  appear  definitely  dependent  u]Don  the  age 
of  the  drift  except  that  the  Late  Wisconsin  soils  are  in  general  richer 
in  potash  than  those  of  the  earlier  formations.  This  relationship  is 
confined  to  the  prairie  soils,  there  being  none  within  the  timbered 
uplands.  Hopkins  and  Pettit  explain  this  by  the  assumption  that  ero- 
sion keeps  a  comparatively  fresh  and  unleached  stratum  constantly 
near  the  surface  in  the  case  of  the  latter. 

In  a  recent  study  of  Iowa  soils  very  similar  in  conception  to  that  of 
the  Illinois  workers.  Brown  (9)  compares  Late  Wisconsin  drift  soils 
with  the  Kansan  drift  soils  lying  just  to  the  east.  Following  the  prac* 
tice  of  Iowa  geologists,  he  designates  as  lowan  the  drift  sheet  which 
Leverett  regards  as  an  integral  part  of  the  Kansan.  Like  Hopkins  and 
Pettit  he  divides  his  soil  column  into  three  sections,  soil  0-6^  inches, 
subsurface  soil  67^3-20  inches,  and  subsoil  20-40  inches.  He  reports 
neither  anv  physical  constants  of  his  samples  nor  the  soil  types  from 
which  they  were  taken,  most  of  them  probably  being  taken  from  unsur- 
veyed  counties. 

The  Late  Wisconsin  soils  were  collected  from  three  dififerent 
counties — Clay,  Kossuth  and  Boone — and  the  Kansas  from  six  differ- 
ent counties^Cerro  Gordo,  Floyd,  Bremer,  Blackhawk,  Buchanan  and 
Delaware.  Thus  the  most  easterly  of  his  Kansas  fields  were  about  200 
miles  east  of  his  most  westerly  Late  Wisconsin  field. 


Table  3. — Difference  in   composition  of  lozva  soils  on   Kansan   (or  loivan) 
and  Late  JVisconsin  drifts,  as  shoum  by  data  of  Broivn. 


Depth 
Inches 

Nit 
Kansan 
per  cent 

10  gen 

Late  Wis. 
per  cent 

Phosphoric  acid 
Kansan            Late  Wis. 
per  cent              per  cent 

Potatsh 
Kansan           Late  Wis. 
per  cent            per  cent 

0-6.6 
6.6—20 
20-40 

.226 
.142 
.056 

.273 
.200 
.071 

.147               .160 
.126                126 
.097               .124 

1.33               1.72 

1.44  1.67 

1.45  1.55 

Depth 
Inches 

I, 

Kansan 
per  cent 

ime 

Late  Wis. 
per  cent 

Carhon  Dioxide 
Kansan            Late  Wis. 
per  cent              per  cent 

Frequency  of  acidity 
Kansan           Late  Wis. 
per  cent              per  cent 

0—6.6 
6.6—20 
20—40 

0.63 
0.63 
0.58 

1.33 
1.01 
6.02 

0.018             0.025 
0.015             0.035 
0.016             2.970 

90                  12 
66                   0 
70                   0 

A  summary  of  his  data  is  reported  in  table  3.  He  finds  the  Late 
Wisconsin  soils  much  richer  in  total  lime,  from  60  to  1100  per  cent  in 
all  three  levels,  while  the  carbonates  differ  little  except  in  the  lowest 


17 

level,  in  which  on  tlic  hiter  drift  they  are  abundant.  An  acid  reaction 
is  usually  found  in  all  three  levels  on  the  Kansan  but  only  rarely  on  the 
Late  Wisconsin,  and  then  only  in  the  surface  section.  On  the  latter 
drift,  the  total  potash  was  much  higher  in  the  first  two  sections  and 
slightly  higher  in  the  third,  while  nitrogen  was  considerably  higher  in 
all  three  levels.  In  both  the  fir.st  and  third  .sections  the  total  phosphoric 
acid  averaged  higher  (^n  the  Late  Wisconsin,  while  the  subsurface 
showed  no  difference. 

AIcMiller  (25)  in  an  investigation  of  the  soils  of  the  most  south- 
erly tier  of  counties  in  iNIinnesota,  begun  in  the  autumn  of  1913  and 
almost  completed  before  the  appearance  of  the  Brown  report,  con- 
ducted a  somewhat  parallel  study.  It  dififered  in  general  conception 
from  the  former  in  that  only  virgin  fields,  and  these  on  till  plains  and 
terminal  moraines,  were  selected ;  the  sampling  was  in  three  one-foot 
sections,  five  fields  being  dealt  with  in  each  county.  The  proportion  of 
gravel  and  the  moisture  equivalent  are  reported  for  every  sample,  thus 
permitting  a  read}  recognition  of  the  general  character  of  the  soil  and 
even  the  identification  of  the  soil  type. 

Five  of  the  fields  sampled  by  McMiller  were  on  the  Kansas,  all 
these  being  near  Spring  Valley  and  on  Carrington  loam,  while  24  were 
on  the  Late  Wisconsin,  four  near  Albert  Lea.  five  near  Wells,  five  near 
Fairmont,  five  near  Jackson,  five  near  Worthington  and  five  near 
Adrian.  These  24  fields  were  distributed  among  five  different  types. 
Carrington  loam,  Carrington  silt  loam,  Fargo  silt  loam,  Fargo  clay 
loam  and  Barnes  silt  loam.  When  the  averages  for  the  five  fields  near 
Spring  Valley  are  compared  with  those  for  the  three  on  the  same  soil 
type  near  Albert  Lea.  which  constituted  the  most  easterly  Late  Wiscon- 
sin fields,  they  being  about  50  miles  to  the  west,  no  great  differences  in 
properties  are  shown  (Table  4).  However,  when  the  averages  of  all 
the  Late  Wisconsin  fields  are  compared  with  those  of  the  five  Kansan 
the  differences  are  more  similar  to  those  reported  by  Brown. 


Table  ./. — Comparison  of  Carrington  loam  at  Spring  Valley,  on  the  Kansan, 
xvith  that  at  Albert  Lea,  on  the  Late  Wisconsin,  from  McMiller's  data. 


Depth 
Feet 

Coarser  fragments 
Kansan           Late  Wis. 
per  cent            per  cent 

Moisture  equivalent 
Kansan           Late  Wis. 
per  cent             per  cent 

Nitrogen 
Kansan           Late  Wis. 
per  cent             per  cent 

1 

2 
3 

0.47               0.00 
1.28               0.53 
1.49               0.89 

23.8               23.1 
19.6               21.1 
16.6               20.6 

.190               .220 
.076               .118 
.030               .063 

Total  phosphoric  acifl 

Total  potash 

Carbon  dioxide 

1 
2 
3 

.15                 .15 
.09                 .10* 
.09                 .15* 

1.85                   1.83* 

1.77               1.94* 
1.57               1.90* 

.05                      .05 

.03                 .05 
.01                 .05 

•Average   of  four  fields,   including  one  on  Carrington  silt  loam. 


18 


FIELD  WORK. 

Selection  of  Fields. 

The  three  types  mentioned  above,  viz..  the  Carrington  silt  loam, 
an  upland  prairie  type,  the  Fargo  silt  loam,  a  lowland  prairie  type,  and 
the  Carrington  loam,  a  forest  type,  were  selected  for  study  on  both 
drifts. 

The  fields  selected  to  represent  these  types  on  the  Kansan  are 
located  in  the  township  of  Wheeling  in  the  eastern  part  of  the  county 
with  the  exception  of  one  just  over  the  north  line  of  this  (Fig.  3).  The 
fields  of  Carrington  silt  loam  and  Fargo  silt  loam  sampled  on  the  Late 
Wisconsin  are  in  the  townships  of  Warsaw  and  Morristown  in  the 
southwestern  part  of  the  county,  while  those  of  Carrington  loam  on  this 
drift  were  selected  in  the  townships  of  Walcott  and  Cannon  City,  none 
l)eing  far  distant  from  the  city  of  Faribault. 

The  Marshall  silt  loam,  a  type  developed  upon  loessial  material 
derived  entirely  from  pre- Wisconsin  drifts  and  confined  to  the  Kansan 
side  of  the  dividing  line,  was  studied  in  addition  to  the  three,  just  men- 
tioned. 

In  selecting  the  individual  fields  it  was  the  aim  to  secure  those  in 
as  nearly. their  virgin  condition  as  it  was  possible  to  obtain  them.  This 
is  e.xtremely  important  since,  as  has  recently  been  pointed  out  by  Glinka 
(16  p.  96),  the  formation  of  soil  horizons  which  are  within  reach  of 
the  plow  is  not  uncommon.  Not  a  single  entire  field  of  upland  prairie 
was  found.  So,  in  the  case  of  the  Carrington  silt  loam  the  task  of 
locating  suitable  tracts  from  which  to  take  samples  was  difficult.  Prac- 
tically all  the  samples  taken  on  this  type  were  from  along  line  fences  or 
beside  roadways  which  it  seemed  certain  had  never  been  plowed.  Since 
they  were  so  easily  brought  under  the  plow  it  is  not  surprising  that 
entire  fields  still  in  an  actually  virgin  condition  on  this  type  are  no 
longer  to  be  found.  At  the  time  of  the  field  work  a  few  of  the  original 
settlers  were  still  living  and  these  were  able  to  give  much  valuable 
information.  Each  field  was  selected  only  after  the  oldest  settlers  in 
the  neighborhood  had  been  consulted  and  a  more  or  less  complete  his- 
tory of  the  field  had  been  obtained.  Thus  in  the  case  of  one  field,  IV, 
on  the  Marshall  silt  loam  it  was  found  that  an  old  settler  living  within 
half  a  mile  of  it  had  cleared  off  the  brush  and  plowed  the  adjacent  field 
in  1858  and  had  seen  it  every  year  since. 

In  the  case  of  the  Fargo  silt  loam  virgin  fields  were  not  so  difficult 
to  find.  On  the  Kansan,  two  rather  poorly  drained  meadows,  both  of 
which  were  plowed  a  few  days  after  the  samples  were  taken,  formed 
two  of  the  fields,  the  grassy  roadsides  two  others,  and  a  line  fence 
border  the  fifth,  while  on  the  Late  Wisconsin  all  were  from  line  fence 
borders  or  beside  roadways. 


RICE   COUNTY 


Shtse/ea'area;  JLa/e  JV/scons/n  DriTt  C/nshae^e//area;  Aa^s<^n  Dr/Tf. 
A  HeJe/s  on  Carr/n^f^on  ^//fAo(sm. 
+  rie/c/s  on  /^r^o ^//f  Loam  '> 

•  F/eMs  on  Carrinaf'on  Loam  \ 

m  Fie/e/s  on  Marsna//  L  oa/n  ,  ^ . 


the  fields  sampled  un  each. 

Fig.  3. — Map  of  Rice   County.  s]iouint>   the  position   of  tlie  two   drifts  and 


PLATE  III 


Illustration  of  the  Character  of  the  Only  Remaining  Unplowed  Tracts  on 
THE  Carrington  Silt  Loam. 

1.     Fence  row  on  the  Kansan,  field  V. 

2.     Roadside  strip  on  the  Late  Wisconsin,  field  II. 


19 

Satisfactory  hclcls  on  tlie  Carrington  loam  were  comparatively 
easy  to  locate,  the  re(.|uired  number  of  pro])crly  distributed  forested 
areas  being  easily  found. 

On  the  Marsiiall  silt  loam,  three  of  the  five  fields  sampled  were 
forested.  For  the  other  two,  the  sets  of  samples  were  taken,  in  one  case 
alone:  a  line  fence  and  in  the  other  by  the  side  of  a  roadway,  neither  of 
which,  within  the  recollection  of  old  settlers  in  the  neighborhood,  had 
ever  been  plowed.  Land  adjacent  to  the  last  two,  however,  had  been 
cleared  of  the  forest  for  many  years  and  given  over  to  mixed  farming 
and  hence  it  is  probable  that  they  also  were  originally  in  forest.  These 
two  are  designated  as  "cleared  fields." 

In  the  case  of  each  tyi>e  an  effort  was  made  to  locate  the  five  fields 
so  that  no  two  would  be  less  than  a  mile  apart  and  usually  this  was 
found  possible.  On  the  Marshall  silt  loam  three  of  the  fields  were  a 
little  less  than  this  distance  a])art. 


Method  of  Sampling. 

Five  fields  (  Fig.  3)  on  each  of  the  types  chosen  on  the  two  drifts 
were  selected  and  from  each  one  of  these  two  sets  of  samples  were 
taken,  the  samples  of  each  set  being  composites  from  ten  borings 
made  approximatel}-  10  yards  apart  and  to  a  depth  of  3  feet.  The  sur- 
face foot  was  taken  in  two  6-inch  sections  so  that  samples  from  4  dif- 
ferent depths  were  obtained,  viz.,  1-6,  7-12.  13-24  and  25-36  inches. 
Two  augers,  one  2.0  and  the  other  1.5  inches  in  diameter,  were  used  in 
the  work,  the  larger  being  employed  to  take  the  surface  section  and  to 
enlarge  the  hole  preparatory  to  taking  the  lower  sections  with  the 
smaller.  Care  was  taken  to  prevent  the  samples  from  the  lower  sec- 
tions becoming  contaminated  with  the  soil  from  the  upper  part  of  the 
hole  as  the  auger  was  withdrawn.  The  composites  of  ten  borings  are 
designated  "Set  1  samples''  and  "Set  2  samples."  while  the  composites 
made  up  in  turn  from  these,  and  so  representing  twenty  borings,  are 
referred  to  as  the  "field  samples."  The  so-called  "drift  samples"  for 
each  type  were  secured  by  combining  equal  weights  of  the  "field  sam- 
ples,'' and  so  are  composites  from  100  borings  scattered  over  a  consid- 
erable territorv. 


20 


EXPERIMENTAL. 

A.    Relative  Fineness  of  Texture. 

When  taking  samples  the  fragments  larger  than  2mni.  in  diameter 
that  were  hrought  up  by  the  auger  were  included  in  the  sample.  In 
cases  where  a  pebble  an  inch  in  diameter  or  larger  obstructed  the  way  a 
new  boring  was  made.  No  attempt  was  made  to  ascertain  the  amount 
of  coarse  gravel  or  of  rock  fragments  of  still  larger  size.  On  glaciated 
areas  such  as  these  this  would  vary  considerably  from  place  to  place 
and  its  determination  would  involve  the  handling  of  large  amounts  of 
soil  and  subrjil  in  the  field. 


1.  Proportion  of  Coarser  Fragments. 

The  J  percentage  of  the  coarser  material,  as  above  defined,  and  the 
average  \/eight  of  the  fragments  (Tables  5  to  12)  were  determined  in 
all  the  field  samples.  These  data  also  serve  as  a  rough  index  of  the 
varying  amounts  of  coarse  gravel  and  boulders  present  in  the  different 
sections  and  on  the  two  drifts. 

Carrington  Silt  Loam.  On  the  Kansan  (Table  5)  the  average  per- 
centages found  for  the  three  foot  section  in  the  different  fields  are  very 
similar,  while  the  differences  between  the  amounts  found  in  the  corre- 
sponding sections  are  small,  the  maximum  being  found,  as  would  be 
expected,  in  the  third  foot-section.  The  average  for  all  sections  of  the 
5  fields  is  o.51  per  cent. 

Table  5. — Coarse  grat'el  in  the  different  sections  from  the  five  fields  on  Car- 
rington silt  loam. 


Depth 
Inches 


1—  6 

7—12 
13—24 
25-36 
Average 

1—36* 


1—  6 

7—12 

13—24 

25—36 

Average 

1—36 


Field 

I 

per  cent 


0.06 
0.04 
0.13 
1.08 

0.42 


0.17 
0.51 
1.32 
1.94 


1.20 


Field 

II 

per  cent 


0.52 
0.68 
0.37 
0.77 


0.58 


Field 

III 

per  cent 

1.     Kansan. 

0.23 
0.33 
0.31 
1.15 

0.55 


Field 

IV 

per  cent 


0.15 
0.21 
0.13 
1.06 

0.46 


2.     Late  Wisconsin. 


1.18 
1.08 
0.91 
2.85 

1.63 


1.00 
1.25 
2.83 
3.44 


2.46 


1.03 
1.38 
1.91 

2.59 

1.90 


Field 

V 

j>er  cent 


0.12 

0.50 
0.14 
1.15 

0.53 


0.99 
0.98 
2.38 
4.32 


2.56 


Average  for 

5  fields 

per  cent 


0.22 
0.35 
0.22 
1.04 


0.51 


0.88 
1.04 
1.87 
3.03 


1.95 


*To  secure  the  averages  for  the  3  foot-sections  the  percentages  from  the  two  6-inch 
sections  were  averaged  and  this  result,  in  turn  averaged  with  the  percentages  for  the  two 
lower  sections.     This  procedure  was  followed  for  all  tables  reported  hereafter. 


21 

The  percentaq-es  found  for  the  Late  W  iscoiisin  are,  on  the  aver- 
ao^e,  280  per  cent  hig^her  than  those  for  the  Kansan.  It  is  evident  from 
this  that  the  processes  of  weatherini,^  are  the  more  advanced  on  the 
older  de])osit.  An  examination  of  the  i)articles  shows  that  shales,  lime- 
stones, and  cherty  rocks  are  much  more  abundant  on  the  voune^er  for- 
mation, having-  practically  disappeared  from  the  older. 

For  this  type  the  average  weight  (Table  6)  of  the  gravel  particles 
brought  up  by  the  auger  is  very  uniform,  showing  little  variation  from 
field  to  field  or  from  drift  to  drift. 


Table  6. — Average  i^.'eight  of  coarse  grgrel  f'artirlrs  in  I  he  different  sections 
from  the  fize  fields  on  Carringtoit  silt  loam. 


Field  Field  Field  Field  Field  Average  for 

Jiepth  I  II  III  IV  V  5  fields 

Inches  granus  grams  grams  grams  grams 


grams 


1.     Kans.\n. 


1—  6  .022  .022  .043  .020  .018  .02.^ 

7—12  .019  .031  .043  .020  .064  .035 

13—24  .017  .020  .031  .016  .023  .021 

25—36  .043  .021  .044  .024  .032  .033 

.Vverage 

1-36  .027  .022  .039  .020       '         .032  .028 

2.     Late  Wisconsin. 

1—  6  .020  .045  .037  .026  .065  .039 

7—12  .018  .032  .024  .031  .027  .026 

13—24  .024  .010  .027  .028  .031  .024 

25—36  .020  .023  .027  .022  .027  .024 

Average 

1—36  .021  .024  .028  .026  .035  .027 


Fargo  Silt  Loam.  The  general  distribution  (Table  7)  of  coarser 
fragments  is  much  the  same  as  on  the  Carrington  silt  loam,  the  maxi- 
mum being  in  the  third  foot  and  on  the  average  only  25  per  cent  as 
much  on  the  Kansan  as  on  the  later  formation.  On  the  former,  three 
fields,  T,  III  and  V.  show  little  or  no  coarse  gravel  in  the  surface  foot, 
while  only  one,  II,  shows  as  much  as  1.0  per  cent  in  the  lowest  section. 
On  the  Late  Wisconsin  the  range  is  from  0.23  per  cent  to  4.38  per  cent, 
with  an  average  of  1..^0  per  cent  for  the  three  foot  section  on  the  five 
fields. 

riie  average  weights  for  the  gravel  particles  (  Table  8)  are  quite 
similar  both  from  field  to  field  and  on  the  two  drifts.  The  second  foot- 
section  from  Field  III  on  the  Kansan  shows  the  highest  average  of  all 
the  field  samples,  but  this  was  due  to  the  inclusion  of  several  stones 
larger  than  those  one  is  ordinarily  able  to  bring  up  with  the  auger. 


22 

Table  7. — Coarse  i!,ravcl  in  the  different  sections  from  the  five  fields  on  Fargo 
silt  loam. 


Depth 
Inches 


1—  6 

7—12 
13—24 
25—36 
Average 

1—36 


1—  6 

7—12 

13—24 

25—36 

Average 

1—36 


Field 
I 

per  cent 


0.00 
0.00 
0.00 
0.36 

0.12 


0.67 
1.00 
0.94 
1.65 

1.14 


Field 
II 

per  cent 


0.35 
0.17 
0.16 
2.21 


0.23 
0.23 
0.79 
1.06 

0.69 


Field 

III 

per  cent 

1.     Kansan. 

0.00 
0.00 
0.20 

017 


Field 

IV 

per  cent 


0.00 
0.70 
0.27 
0.85 


0.8«  0.12  0.49 

2.     Late  Wiscon.sin. 


0.64 
1.06 
1.51 
2.07 

1.48 


0.58 
1.44 
4.28 
4.38 

3.22 


Field 

V 

per  cent 


0.00 
0.07 
0.36 
0.82 

0.40 


0.46 
0.83 
0.68 
1.57 

0.96 


Average  for 

5  fields 

per  cent 


0.07 
0.19 
0.20 
0.88 


0.40 


0.52 
0.91 
1.64 
2.15 

1.50 


Table  8. — Average  weight  of  coarse  gravel  particles  in  the  different  sections 
on  Fargo  silt  loam. 


Deptl 
Inche 


1—  6 

7—12 

13—24 

25—36 

Average 

1—36 


1—  6 

7—12 

13—24 

25—36 

Average 

1—36 


Field 

I 

grams 


.000 
.000 
.000 
.046 

.015 


.025 
.025 
.023 
.030 

.026 


Field 

11 
grams 


.011 

.020 
.017 
.029 


.027 
.019 
.025 
.020 

.023 


Field 
III 

grams 

1.    Kansan. 

.000 
.011 
.193 
.028 


Field 
IV 

grams 


.000 
.049 
.030 
.081 


.020  .075  .045 

2.     Late  Wiscon.sin. 


.023 
.014 
.017 
.018 

.018 


.020 
.022 
.051 
.025 

.032 


Field 

V 
grams 


.000 
.017 
.024 
.044 

.025 


.014 
.018 
.015 
.020 

.017 


Average  for 
5  fields 
grams 


.002 
.019 
.053 
.046 


.036 


.022 
.020 
.026 
.023 

.023 


Carrington  Loam.  On  both  drifts  (Table  9)  the  variation  from 
field  to  field  is  much  greater  than  with  the  two  other  types.  Here  also 
in  general  the  maximum  is  found  in  the  third  foot.  The  average  for 
the  five  fields  is  somewhat  the  higher  on  the  Kansan,  the  opposite  of 
what  was  found  for  the  two  other  types.  This  is  caused  by  the  excep- 
tionally high  percentages  for  the  third  foot  of  Fields  I,  II  and  III  on 
the  older  drift.  The  topography  of  this  type,  as  mentioned  above 
(p.  12)  is  the  most  rolling  of  any  sampled  and  accordingly  the  soil  is 
the  most  apt  to  be  stronglv  eroded,  hence  it  is  not  unlikely  that  much 
of  the  material  originally  at  the  surface  on  these  three  fields  has  been 
carried  away,  thus  l)ringing  less  weathered  layers  within  the  three 
foot  section. 


23 


Table  9 

. — Coarse 

i^rnzcl  ill  the 

different  sec 

tions  from 

Ihe  /ire  fit 

•Ids  on  Car- 

ring,ton  loam. 

Field 

Field 

Field 

Field 

Field 

Average  for 

Dei 

.ih 

I 

II 

III 

IV 

V 

S  fields 

Inc 

hi> 

per  cent 

per  cent 

1 

per  cent 

Kansan. 

per  cent 

|icr  cent 

per  cent 

1- 

-  6 

0.93 

0.33 

0.53 

0.03 

2.03 

0.77 

7- 

-12 

1.02 

0.31 

0.63 

0.13 

0.03 

0.42 

13- 

-24 

2.52 

1.28 

1.93 

0.19 

0.02 

1.19 

25- 

-36 

6.22 

6.48 

8.24 

0.04 

0.08 

4.21 

Average 

1- 

-36 

3.23 

2.6<> 

3.58 

0.10 

0.38 

2.00 

2.     L 

ATK   WiSCON.SIN. 

1- 

-  6 

0.47 

1.07 

0.64 

1.79 

0.46 

0.89 

7- 

-12 

0.94 

0.75 

0.27 

1.65 

0.26 

0.77 

13- 

-24 

1.52 

1.70 

1.10 

4.25 

0.18 

1.75 

25- 

-36 

1.81 

2.93 

2.90 

4.92 

1.98 

2.91 

Av( 

erage 

1- 

-36 

1.34 

1.85 

1.48 

3.63 

0.94 

1.83 

An  examination  of  the  minerals  in  the  third  foot-section  on  the 
two  drifts  showed  that  on  the  Kansan  considerahly  larger  quantities  oi 
trap  rocks  and  iron  minerals  (limonite,  magnetite,  etc.)  were  present 
than  on  the  Late  Wisconsin,  while  on  the  latter  a  higher  percentage  of 
quartz,  light  colored  quartzite,  chert  and  shales  was  observed,  no  trace 
of  the  two  last  named  rocks  being  found  on  the  Kansan. 

The  average  weight  of  the  gravel  particles  (Table  10 j  in  the  three 
foot  section  is  very  similar  for  all  fields  on  the  Late  Wisconsin  and  for 
Fields  IV  and  V  on  the  Kansan.  The  average  weight  for  the  other 
fields,  I,  II  and  III,  on  the  latter,  is  slightly  higher,  due  to  the  heavier 
particles  found  in  the  third  foot-section. 

Table  10. — Averai^e  iveight  of  eoarse  gravel  particles  in  the  different  sections 
from  the  five  fields  on  Carrington  loam. 


Field 

Field 

Field 

Field 

Field 

Average  for 

IJepth 

I 

II 

III 

IV 

V 

S  fields 

Inches 

grams 

grams 

grams 

1.     Kansan. 

grams 

grams 

grams 

1-  6 

.020 

.026 

.020 

.009 

.035 

.022 

7—12 

.020 

.024 

.026 

.035 

.014 

.024 

13—24 

.033 

.033 

.038 

.037 

.017 

.032 

25-36 

.043 

.039 

.050 

.016 

.027 

.035 

Average 

1—36 

.032 

.032 

.037 

.025 

.023 

.030 

2. 

Late  Wisconsin. 

1—  6 

.019 

.031 

.035 

.026 

.036 

.029 

7—12 

.021 

.025 

.020 

.021 

.015 

.020 

13—24 

.021 

.030 

.023 

.033 

.017 

.025 

25—36 

.021 

.030 

.033 

.030 

.025 

.028 

Average 

1—36 

.021 

.029 

.028 

-.029 

.022 

.026 

24 

Marshall  Sill  Loan.  This  type  has  developed  on  a  loessial  fornin- 
tion  and  accordingly  it  would  not  be  expected  to  carry  many,  if  any, 
fragments  coarser  than  2mm.  The  thickness  of  the  deposit  might  have 
an  influence  on  the  number  of  these  since,  in  case  it  were  shallow,  bur- 
rowing animals  and  insects  might  carry  upward  a  sufficient  amount  of 
the  underlying  till  to  modify  to  a  certain  degree  the  mechanical,  if  not 
the  chemical  composition  of  the  soil  (21,  p.  90-91 V 

On  one  field,  I  (Table  11)  and  in  the  first  set  from  another,  III, 
the  till  was  encountered  in  the  third  foot-section,  Set  2  of  the  latter 
field  being  evidently  entirely  on  the  till,  since  it  carried  as  high  a  per- 
centage of  coarse  fragments  as  any  field  on  the  Carrington  loam.  The 
amounts  found  in  the  two  sets  on  this  field  are  given  below  : 


Depth 

Set  1 

Set  2 

Inches 

per  cent 

per  cent 

1—  6 

.14 

2.25 

7—12 

.14 

.51 

13—24 

.13 

3.50 

25—36 

3.99 

10.17 

The  large  area  of  this  kind  of  soil  west  of  Nerstrand,  upon  which 
Fields  I  and  IIT  are  located  has  a  very  shallow  deposit  of  loess  (11,  p. 
36.),  while  that  to  the  north  and  east,  upon  which  sites  for  Fields  II,  IV 
and  V  were  selected,  appears  to  have  a  greater  thickness  and  accord- 
ingly is  more  representative  of  this  type.  Few  fragments  were  found 
in  the  samples  from  the  three  fields  last  mentioned. 


Tabic    II. — Coarse   gra^'cl  in    the  different  sections  froui    the  Hve  fields   on 
Marshall  silt  loam. 


Depth 
Inches 

Field 
I 

per  cent 

Field 

II 

per  cent 

Field 

III 

per  cent 

1.     Kansan. 

Field 

IV 

per  cent 

Field 

V 

per  cent 

Average  for 

5  fields 

per  cent 

1—  6 

7-12 

13—24 

25—36 

0.06 
0  02 
0.48 
1.92 

0.05 
0.02 
0.00 
0.05 

1.19 

0.32 
1.81 
7.08 

0.00 

0.02 
0.01 
0.00 

0.00 
0.00 
0.00 
0.00 

0.24 
0.07 
0.46 
1.81 

Average 
1—36 

0.81 

0.0.1 

3.21 

0.01 

0.00 

0.81 

Tabic  12. — Average  wciglit  of  coarse  tira-rel  /mrlieles  in  the  different  sections 
from  the  five  fields  on  Marshall  silt  loam. 


Field 

Field 

Field 

Field 

Field 

Average  for 

Depth 

I 

II 

III 

IV 

V 

S  fields 

Inches 

grams 

grams 

grams 

1.    Kansan. 

grams 

grams 

grams 

1—  6 

.011 

.025 

.024 

.000 

.000 

.012 

7-12 

.011 

.013 

.018 

.005 

.000 

.009 

13—24 

.030 

.000 

.040 

.005 

.000 

.015 

25—36 

.032 

.049 

.029 

.000 

.000 

.022 

Average 

1—36 

.024 

.023 

.030 

.003 

.000 

.016 

25 

Discussion.  The  average  percentages  of  coarser  fragments  (Table 
13)  are  higher  in  the  soils  on  the  Kansan  than  in  those  of  the  Late  Wis- 
consin, with  exception  of  the  third  foot-section  of  the  Carrington  loam. 
The  explanation  of  this  exception  appears  to  lie  in  the  fact  that  on  three 
fields  erosion  has  removed  the  surface  material  and  thus  left  the  less- 
weather  portion  nearer  to  the  surface  than  it  is  ordinarily  found.  The 
larger  amount  of  coarser  particles  on  the  younger  formation  may  be 
due  partially  to  a  less  advanced  degree  of  weathering  than  on  the  older 
drift.  This  also  accounts  for  the  different  amounts  of  softer  rocks 
(limestones,  shales  and  cherty  material)  found  on  the  two  drifts, 
these  on  the  older  formation  having  practically  entirely  gfiven  way  to 
the  processes  of  weathering  to  a  depth  greater  than  three  feet. 

Glacial  material  was  encountered  in  the  third  foot  on  two  fields  of 
Marshall  silt  loam,  but  on  the  other  three  the  thickness  of  the  loess 
deposit  was  sufficient  to  he  characteristic. 


Table  13. — Coarse  gravel  iu  the  diifcrciii  sections.  Tin-  data  are  the  aver- 
ages for  the  file  fields  on  each  type  refortcd  iu  the  last  coluiiin  of  tables  5,  7, 
9  and  II. 


Uepih 
Inches 

Caningti 
Kansan 
per  cent 

III  silt  loan: 
Late  Wis. 
per  cent 

Fargo 
Kansan 
per  cent 

silt  loam 
Late  Wis. 
per  cent 

Carrin, 
Kansan 
per  cent 

gton  loam 
Late  Wis. 
per  cent 

Marshall 

loam 

per  cer 

1~   6 
7—12 

13—24 
25—36 

0.22 
0.35 
0.22 
1.04 

0.88 
1.04 
1.87 
3.03 

0.07 
0.19 
0.20 
0.88 

0.52 
0.91 
1.64 
2.15 

0.77 
0.42 
1.19 
4.21 

0.89 
0.77 
1.75 
2.91 

0.24 
0.07 
0.46 
1.81 

Average 
1—36 

0.51 

1.95 

0.40 

1.50 

2.00 

1.83 

0.81 

The  average  weight  of  the  gravel  particles  (Table  14)  found  in 
the  three-foot  section  was  much  the  same  from  type  to  type  and  from 
drift  to  drift,  that  of  those  found  on  the  Kansan  being  slightly  higher 
than  that  of  those  on  the  Late  Wisconsin,  the  difference  being  greatest 
on  the  Fargo  silt  loam. 


Fable  14. — Average  weight  of  coarse  gravel  particles  in  the  ditferent  sections. 
The  data  are  the  averages  for  the  five  fields  on  each  type  reported  in  the  last 
column  of  tables  6,  8,  10  and  12. 


Depth 
Inches 

Carrington 
Kansan 
grams 

silt  loam 

Late  Wis. 

grams 

Fargo 
Kansan 

grams 

silt  loam 
Late  Wis. 
grams 

Carrington  loam 
Kansan       Late  Wis. 
grams             grams 

Marshall  silt 
loam 
gram* 

1- 

7— 

13- 
25- 

-  6 
-12 
-24 
-36 

.025 

.035 
.021 
.033 

.039 
.026 
.024 
.024 

.002 
.019 

.053 
.046 

.022 
.020 
.026 
.023 

.022 
.024 
.032 
.035 

.029 
.020 
.025 
.028 

.012 
.009 
.015 
.022 

.\verage 
1—36 

.028 

.027 

.036 

.023 

.030 

.026 

016 

26 


2.  Texture  of  Fine-earth. 


As  the  most  satisfactory  method  of  ascertaining  the  similarit)'  in 
texture  of  the  fine-earth  of  the  samples  used  in  this  study  the  determi- 
nation of  the  moisture  equivalent  (7)  was  selected.  The  relation  of 
this  to  the  mechanical  composition  and  other  physical  constants  has 
been  discussed  by  various  authors  as  mentioned  above. 

The  moisture  ecjuivalents  of  the  samples  in  the  two  sets  from 
each  field  were  determined  (Tables  15  to  18).  The  data  in  Table  15. 
the  first  part  of  table  16  and  those  for  Field  T  in  the  first  part  of  table 
17,  are  the  means  of  duplicate  determinations,  the  others  being  derived 
from  single  determinations.  The  concordance  of  duplicate  determina- 
tions may  be  illustrated  by  the  results  from  the  136  samples  mentioned, 
only  two  showing  a  difl:'erence  greater  than  unity.  Another  illustration 
is  afforded  by  the  data  in  table  19. 

Carrington  Silt  Loam.  On  the  Kansan  Drift  this  type  showed 
(Table  15)  very  little  variation  from  set  to  set  within  the  same  field 
and  but  a  slightly  greater  one  from  field  to  field,  the  latter  being  the 
most  marked  in  the  two  sections  from  the  surface  foot  where  there  was 
also  the  greatest  variation  in  the  percentage  of  organic  matter  (6,  p. 
18).  The  highest  value,  ZZ.S,  was  found  in  the  surface  section,  and 
the  lowest,  22.1,  in  the  third  foot. 

On  the  Late  Wisconsin  the  variation  from  field  to  field  was  no 
greater  than  on  the  Kansan,  but  in  Field  III  the  first  set  averaged  only 
20.5  and  the  second  26.7,  compared  with  34.8  for  Set  2  from  Field  I. 
The  latter  field  differs  markedly  from  the  four  others  on  this  drift  and 
shows  the  highest  value  of  all  the  fields  sampled  on  this  type,  those  for 
the  four  sections  ranging  only  from  ZZ.Z  to  2>?.?^:  The  averages  for  the 
five  fields  on  the  two  drifts  are  very  similar. 

Fargo  Silt  Loam.  (")n  the  Kansan  (Table  16)  this  type  shows  little 
variation  either  within  the  same  field  or  from  field  to  field,  but  on  the 
Late  Wisconsin  there  is  a  somewhat  wider  variation  in  both.  The 
range  is  from  23.1,  found  in  the  subsoil  to  52.5  in  the  surface.  The 
averages  for  the  surface  6-inch  sections  on  the  two  drifts  show  a 
marked  difference,  that  for  the  Kansan  being  45.9  compared  with  35.9 
on  the  other.  This,  in  all  probability,  is  due  to  the  larger  amount  of 
organic  material  in  the  fonner  (6,  p.  18)  as  indicated  by  the  per- 
centages of  organic  carbon  (Table  53),  nitrogen  (Table  57)  and  vola- 
tile matter  (Table  52).  On  the  Kansan  the  organic  carbon  rises  to 
9.47  per  cent  compared  w  ith  5.71  on  the  Late  W^isconsin. 


27 


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•     29 

Carringtoii  J.odiit.  There  is  considerable  variation  in  texture 
within  the  in(Hvichuil  tieUls  and  from  field  to  field  (Table  17)  on  the 
Kansan.  tiiis  beini,""  more  pronounced  in  the  third  foot,  sugsestinsr  that 
at  this  depth,  disintegration  has  not  proceeded  as  far  on  the  younger 
drift.  ( )n  the  Late  Wisconsin,  the  variation  within  the  same  field  and 
from  field  to  field  is  not  so  great.  Rurke  and  Kolbe  (11,  p.  22),  in 
describing  this  type,  state  that  "the  texture  of  the  surface  soil  is  for 
the  most  part  uniform,  but  the  color  and  depth  are  variable.  Areas  of 
minimum  depth  apparently  have  resulted  from  erosion,  those  of  maxi- 
mum depth  representing  more  probably  the  natural  conditions." 

It  is  to  be  observed  that  the  moisture  e(|uivalent  is  in  most  cases 
higher  for  the  second  foot-section  than  for  the  6-inch  section  above 
this.  The  organic  matter  in  forest  soils,  such  as  the  Carrington  loam,  is 
low  even  in  the  surface  six  inches  and  a  lack  of  this,  coupled  wnth  the 
translocation  of  clay  particles  downward  into  the  second  foot  may 
account  for  this  rather  regular  variation.  The  averages  range  from 
24.8  in  the  surface  section  to  16.9  in  the  subsoil. 

Marshall  Silt  Loam.  On  this  type  (Table  18)  considerable  \aria- 
tion  wnthin  Fields  IT  anrl  I\'  is  shown  and  especially  great  differences 
between  Set  1  from  Field  II  and  Set  2  from  b'ield  I\',  the  former  aver- 
aging 16.3  and  the  latter  27.6,  or  nearly  70  per  cent  higher.  To  elim- 
inate any  chance  of  differences  in  speed  of  the  centrifuge,  etc.,  causing 
this,  the  corresponding  samples  from  these  two  fields  were  run  side  by 
side  (Table  19).     It  will  be  seen  that  these  agree  very  closely  with  the 

Table    ig. — Moisture    equivalents   of  sain/^lcs  from    tzvo   fields   of   Marsluill 
silt  loam. 

Field  II,   Set  1 
Depth  Det.  Det. 

Inches  1  2  Av. 

1—  6  18.5  17.8  18.2 

7—12  16.0  16.5  16.3 

13—24  15.9  15.5  15.7 

25—36  15.7  15.1  15.4 

first  determinations,  so  great  a  variation  either  within  the  same  field  or 
between  the  dift"erent  fields  on  this  type  was  not  anticipated.  From  its 
loessial  origin,  a  texture  more  uniform  than  that  on  a  type  developed 
on  the  till  was  to  have  been  expected.  In  Fields  IV  and  V  the  moisture 
equivalents  for  the  different  sections  are  distinctly  higher  than  in  the 
three  other  fields.  The  area  in  which  the  former  two  are  located  while 
originally  on  the  very  fringe  of  the  forest  has,  for  many  years,  been 
clear  even  of  brush  and  the  fields  on  both  sides  of  these  "fence  row" 
fields  have  been  kept  under  mixed  farming  conditions,  which  has  per- 
mitted an  accumulation  of  organic  matter  somewhat  similar  to  that 
which  would  accrue  under  prairie  conditions.  While  this  might  account 
for  the  greater  moisture  holding  capacity  in  the  surface  foot  it  could 
not  explain  the  variation  in  the  lower  sections. 


Det. 

1 

Field  IV,  Set  2 

Det. 

2 

Ay. 

30.3 

30.4 

30.3 

30.0 

30.4 

30.2 

28.2 

27.9 

28.0 

25.1 

25.5 

25.3 

30 

Discussion.  The  averages  for  the  five  fields  on  the  different  types 
(Table  20)  show  little  variation  from  drift  to  drift.  On  the  Kansan 
the  Fargo  silt  loam  appears  to  have  a  finer  texture  in  the  two  upper 
sections  than  in  the  corresponding  ones  on  the  Late  Wisconsin,  but  this 
is  probably  due  to  the  higher  content  of  organic  matter  on  the  former. 

Table  20. — Moisture  equivalents  of  samples  from  the  different  types  on  the 
tzvo  drifts.  The  data  are  averages  for  the  five  fields  reported  in  tables  15  to  18 
inclusive. 


Depth 
Inches 

Carrington 
Kansan 

1   silt  loam 
Late  Wis. 

Fargo 
Kansan 

silt  loam 
Late  Wis. 

Carrin 
Kansan 

igton  loam 
Late  Wis. 

Marshall 
loam 

1—  6 

7—12 

13-24 

25—36 

30.6 
30.1 
28.1 
24.1 

29.6 

27.7 
25.7 
25.9 

45.9 
37.2 
30.1 
25.1 

35.9 

32.8 
30.3 
29.5 

24.8 
22.0 
22.6 
16.9 

24.4 

20.6 
21.9 
20.5 

25.4 
23.3 
22.9 
19.1 

Average 
1—36 

27.5 

26.7 

32.2 

31.4 

21.0 

21.6 

22.1 

The  Carrington  loam  shows  a  more  pronounced  variation  in  tex- 
ture from  drift  to  drift  than  is  found  with  the  other  types,  this  being 
greatest  in  the  third  foot-section.  However,  the  averages  for  the  five 
fields  on  the  two  drifts  are  very  similar. 

To  obtain  the  true  moisture  equivalent  a  correction  for  the  coarse 
gravel  would  need  to  be  made,  but  this  does  not  afifect  the  actual  water- 
holding  capacity,  since  the  rock  fragments  neither  increase  or  decrease 
the  amount  of  water  held  by  the  fine-earth. 

The  uniformity  in  texture  on  the  same  type  on  both  drifts  shows 
that  the  U.  S.  Bureau  of  Soils  Surveyors  were  fully  justified  in  their 
classification.  Other  differences  are  not  so  apparent  in  the  field  and  are 
brought  out  only  by  a  laboratory  investigation. 

The  moisture  equivalents,  computed  from  the  mechanical  analysis 
(Table  1)  by  formulas  proposed  by  Briggs  and  Shantz  (8,  p.  73)  and 
Alway  and  Russel  (5,  p.  842)  do  not  agree  satisfactorily  with  those 
obtained  by  direct  determination,  although  the  values  found  by  the 
Alway  and  Russel  formula  for  the  two  cleared  fields  on  the  Marshall 
silt  loam  resemble  very  closely  those  found  by  direct  determination. 
This  is  to  be  expected,  since  this  formula  was  developed  for  loessial 
soils  only,  and  it  was  pointed  out  (5,  p.  843)  that  different  formulas 
would  be  required  for  various  soil  types.  The  most  marked  difference 
between  the  computed  and  actual  values  is  found  with  the  surface  soil 
on  the  Fargo  silt  loam,  where  the  former  are  much  too  low. 


CARRINGTON  LOAM 


Fig.  4. — Diagram    showing   the   mean   moisture   equivalents   of   the   different 
types  on  both  drifts. 


IM.ATK    IV 


'^iM'^.j^L  «HL._ 


I;L^y^^^Aij[N_.G' Toi'odu Ai'H  V  ()\  I'"auc,(i  Sii.t  Loam. 

1.  Field  III — on  the  Kansan,  the  broad  roadside  strip  on  the  left. 

2.  Field   11 — on   the   Late   Wisconsin,   at  the   foot   of  the  slope   and  to  the 
right  of  the  fence. 


31 
B.  LIME  SUPPLY. 

1.  Carbonates. 

The  carbon  dioxide  in  the  field  samples  is  reported  in  tables  21  to 
23.  Only  one  determination  was  made  for  each  sample,  but  a  check  on 
the  accuracy  of  these  is  furnished  by  the  determination  of  the  amount 
in  the  "drift  samples,"  prepared  by  compositine:  equal  weights  of  the 
five  field  samples.  The  full  agreement  of  these  may  be  seen  from  the 
last  two  columns  in  the  tables. 

Carrington  Silt  Loam.  The  amount  of  carbonates  on  the  Kansan 
is  practically  negligible  and  varies  but  little  from  field  to  field,  the 
average  of  the  carbon  dioxide  in  the  three  foot  section  of  the  different 
fields  falling  between  0.051  and  0.062  per  cent,  with  an  average  for  all 
fiveof  0.057  (Table  21). 


Table 

21. — Carbi 

;;(  dioxide 

/;;   the 

different  se. 

ctioiis  from  the  jive 

fields  on 

Carrington 

silt  loam. 

Field 

Field 

Field 

Field 

Field 

Av.  for 

Drift 

Depth 

I 

II 

III 

IV 

v 

5  fields 

San"ple 

Inches 

per  cent 

per  cent 

per  cent 
1.      ] 

per  cent 

Kansan. 

per  cent 

per  cent 

per  cent 

1—  6 

0.084 

0.052 

0.068 

0.108 

0.072 

0.077 

0.080 

7—12 

0.088 

0.076 

0.080 

0.076 

0.092 

0.082 

0.088 

13—24 

0.045 

0.056 

0.075 

0.064 

0.(M6 

0.057 

0.060 

25—36 

0.031 

0.035 

0.036 

0.016 

0.024 

0.034 

0.033 

Average 

1—36 

0.054 

0.052 

0.062 

0.057 

0.051 

0.057 

0.059 

2 

Late  Wisconsin. 

1—  6 

0.112 

0.112 

0.048 

0.044 

0.064 

0.076 

0.072 

7—12 

0.066 

0.042 

0.047 

0.070 

0034 

0.052 

0.049 

13—24 

0.064 

0.172 

0.348 

0.026 

0.040 

0.130 

0.134 

25—36 

0.060 

1.565 

3.136 

0.026 

0.544 

1.066 

1.057 

Average 

1—36 

0.071 

0.605 

1.177 

0.036 

0.211 

0.420 

0.417 

On  the  Late  Wisconsin  two  of  the  fields,  1  and  IV,  show  a  similar 
low  content,  but  two,  II  and  III,  show  an  appreciable  amount  in  the 
second  and  third  foot-sections,  and  the  fifth,  V,  the  third  foot  only. 
The  maximum,  3.14  per  cent,  is  found  in  the  third  foot  of  Field  III. 

It  is  evident  that  the  carbonate  on  the  Kansan  has  been  leached 
out  to  a  depth  greater  than  three  feet  and  that  the  same  is  true  in  the 
case  of  two  of  the  fields  on  the  Late  Wisconsin,  but  in  general  the  leach- 
ing on  the  latter  has  not  progressed  nearly  so  far. 

Fargo  Silt  Loam.  On  this  type  (Table  22)  the  carbonate  content 
on  the  Kansan  varies  considerably  from  field  to  field,  in  two,  I  and  IV, 
there  being  no  more  than  in  the  Carrington  silt  loam  on  the  same  drift, 
while  in  the  three  others  an  appreciable  amount  was  found  in  the  third 
foot-section.  In  all  four  sections  in  Field  V  the  content  is  compara 
tively  high. 


32 

In  Field  I  on  the  Late  Wisconsin,  the  carbon  dioxide  ranged  from 
2.23  per  cent  in  the  surface  section  to  3.99  in  the  third  foot,  this  field 
being-  the  richest  in  carbonate  of  all  thirty-fi^'e  fields  sam])led.  (  )f  the 
four  other  fields,  TV  is  the  only  one  showing-  an  aj^ipreciable  ([uantit}-, 
this  carrying-  1.03  per  cent  in  the  third  foot-section.  The  others  aver- 
age less  than  0.1  per  cent  for  the  three  feet.  With  this  type  in  general, 
carbonates  are  higher  on  the  Kansan  than  on  the  Late  Wisconsin,  the 
average  for  the  latter  being  high  only  because  of  the  large  amount  in 
Field^I. 


Table  22. — Carbon   dioxide  in   the  different  scelions  fruiii  the  five  fields  on 
I'argo  silt  ioain. 


Ue|)tli 
liirlies 

Field 

1 

per  (.■enl 

Field 
II 

per  cent 

Field 
III 

per  cent 

1. 

Field 

IV 

per  cent 

Kansan. 

Field 

V 
I>er  cent 

Av.  for 
S  fields 
per  cent 

Drift 
Sample 
per  cent 

1—  6 

7—12 

13—24 

25—36 

0.096 
0.060 
0.038 
0.080 

0.080 
0.064 
0.4Q0 

0.096 
0.072 
0.028 
1.000 

0.140 
0.088 
0.006 
0.008 

0.924 
0.672 
0.160 
2.562 

0.314 

0.194 
0.059 
0.828 

0.296 
0.201 
0.064 
0.840 

Average 
1—36 

0.065 

0.371 

0.043 

1.173 

0.380 

0.384 

0  080 

0.094 

0.097 

0.068 

0.511 

0.485 

0.056 

0.108 

0.064 

0.064 

0.540 

0.570 

0.036 

0.080 

0.034 

0.010 

0.530 

0.536 

0.108 

0.036 

1.034 

0.020 

1.037 

1.040 

2.     Late  Wisconsin. 

1—  6  2.230 

7—12  2.410 

13—24  2.500 

25—36  3.990 

Average 
1—36  2.937  0.071  0.072  0.383  0.032  0.697  0.701 

Subsequent  to  the  collection  and  analysis  of  samples  from  Field  1 
it  was  established  that  although  it  appeared,  on  first  inspection,  that 
the  drainage  outlet  was  lower  than  the  lowest  point  in  the  tract,  in 
reality  it  was  some  feet  higher,  the  field  thus  forming  a  part  of  an 
extensive  but  very  .shallow  "pot-hole."  The  drainage  water  accumu- 
lating" in  the  lower  part  of  this  and  evaporating-  would  leave  behind  the 
mineral  constituents  leached  from  the  surrounding-  uplands,  thus  bring- 
ing about  a  concentration  of  these,  and  as  the  drift  was  so  well  sup- 
plied with  limestone  the  carbonate  content  of  the  soil  of  this  field  was 
raised  to  a  high  point. 

Carrington  Loam.  The  quantity  of  carbonate  in  the  Carrington 
lo.im  varies  but  little  from  field  to  field  and  is  practically  nil  on  both 
drifts,  the  soil  having  been  thoroughly  leached  to  at  least  three  feet 
even  on  the  Late  Wisconsin  (Table  23). 

Discussion.  The  average  amounts  of  carbon  dioxide  for  the  five 
fields  on  the  different  types  on  the  two  drifts  are  shown  in  table  24.  On 
the  Late  Wisconsin  the  averages  in  the  three  foot  section  are  higher 
than  on  the  Kansan  with  the  exception  of  those  for  the  Carrington 


3.^ 

Table  2J. — Carbon   dioxide   in   llw  different  sections  from   the   tire  fields  on 
C  arrington  loam. 


Ki.-I.l 

IMCI.I 

FieM 

Field 

Fiel.l 

Av.  for 

Drift 

Depth 

1 

II 

III 

IV 

V 

S  fields 

Sample 

Inches 

per  cent 

per  cent 

per  cent 

per  cent 

per  cent 

per  cent 

per  cent 

1.     K 

\N.'J.\N. 

1- 

-  6 

0.06<) 

0.048 

0.072 

0.088 

0  088 

0.072 

0.W2 

7- 

-12 

0.062 

0.048 

0.052 

0.052 

0.056 

0.054 

0.044 

13—24 

0.032 

0.084 

o.oa, 

0.064 

0.080 

0.053 

0.032 

25- 

-36 

0.046 

0.07() 

0  020 

0.05() 

0.060 

0.051 

0.040 

Averase 

1- 

-36 

0.047 

().0()9 

0.029 

2.       L.\TE 

0.063 
Wisconsin 

0.071 

0.056 

0.047 

1- 

-  6 

0.110 

0.112 

0.062 

0.056 

0.072 

0.082 

0.100 

7- 

-12 

0.086 

0.044 

0.07(. 

0.04(1 

0  056 

O.Ofil 

0.064 

13- 

-24 

0.048 

0.030 

0.040 

0.044 

0.044 

0.042 

0.052 

25- 

-36 

0.026 

0.050 

0.036 

0.108 

0.042 

0.052 

0.044 

Average 

1- 

-36 

0.057 

0.055 

0  048 

0.007 

0.050 

0.055 

0.059 

loam,  where  they  are  ahke  for  the  two  drifts.  On  the  older  formatioi? 
the  carbonates  have  been  leached  out  to  a  depth  greater  than  three  fee? 
on  the  two  Carrington  series.  No  serious  leachinq-  has  taken  place  on 
the  Farcfo  silt  loam  on  either  drift.  On  the  Late  Wisconsin  an  appre- 
ciable amount  is  found  in  the  third  foot  on  the  Carrington  silt  loam,  but 
practically  all  has  been  leached  out  of  the  first  three  feet  on  the  Car- 
rington loam. 

Field  V  on  the  Kansan  and  Field  I  on  the  Late  Wisconsin,  on  the 
Fargfo  silt  loam,  show  a  carbonate  content  radically  different  from  the 
four  other  fields  on  their  respective  drifts,  well  illustrating-  the  fact 
that  samples  from  a  single  field  cannot  safely  be  assumed  to  be  repre- 
sentative of  a  particular  type  in  any  given  area. 

Table  24. — Carbon  dioxide  in  the  different  sections.     The  data  are  averages 
for  the  five  fields  reported  in  column  7  of  tables  3i,  22  and  2^. 

Carrington  silt  loam  Fargo  silt  loam  Carrington  loam 

Depth  Kansan  Late  Wis.  Kansan  Late  Wis.  Kansan  Late  Wis. 

Inches  per  cent  per  cent  per  cent  per  cent  per  cent  per  cent 

1_  6  0.077  0.076  0.314  0.511  0.072  0.082 

7—12  0.082  0.052  0.194  0.540  0.054  0.061 

13—24  0.057  0.130  0.059  0  530  0.053  0.042 

25—36  0.034  1.066  0.828  1.037  0  051  0.052 

Average 

1—36  .0.057  0.420  0.380  0.697  0.056  0.055 


34 

2.  Reaction  With  Litmus. 

The  reaction  of  botli  sets  of  samples  from  each  field  was  tested 
with  litmus  paper.  Strips  of  sensitive  red  and  blue  litmus  paper  were 
placed  in  direct  contact  with  the  soil,  the  latter  was  then  moistened  with 
distilled  water  and  after  a  half  hour  the  reaction  was  noted. 

Carrington  Silt  Loam.  On  the  Kansan  the  soils  of  this  type 
(Table  25)  all  proved  acid,  while  on  the  Late  Wisconsin  the  acidity  was 
found  less  general,  the  lower  two  sections  being  neutral  in  Field  II  and 
in  Set  1  of  Field  TIT.  The  third  foot  in  the  second  set  of  Field  V  is 
also  neutral. 

Table  23. — Acidity  as  found  by  the  litinits  method.    .Samples  taken  from  five 
fields  on  Carrington  silt  loam. 


Depth 
Inches 

Field  I 

Set          Set 

1               2 

Fielc 
Set 
1 

1  II 

Set 

2 

Field 
Set 
1 

Ill 

Set 

2 

Field 
Set 

1 

IV 
Set 

Fie 
Set 
1 

Id  V 

1.     Kansan. 

1—6 

acid 

acid 

acid 

acid 

acid 

acid 

neut. 

neut. 

acid 

neut. 

7—12 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

13—24 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

25—36 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

2. 

Late 

Wisconsin. 

1—  6 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

7—12 

acid 

iient. 

acid 

acid 

acid 

neut. 

acid 

acid 

acid 

acid 

13—24 

acid 

acid 

neut. 

neut. 

neut. 

acid 

acid 

acid 

acid 

acid 

25—36 

acid 

acid 

neut. 

neut. 

neut. 

acid 

acid 

acid 

acid 

neut. 

Fargo  Silt  Loam.  Nearly  all  of  the  soils  on  the  Kansan  (Table 
26)  were  neutral,  the  second  set  from  Field  III  being  the  only  one  of 
the  ten  .sets  in  which  the  reaction  was  acid  for  all  four  sections.  On 
the  Late  Wisconsin  the  acidity  was  more  marked,  approximately  half 
of  the  samples  being  neutral  and  half  acid. 

Table  26. — Acidity  as  found  by  the  litmus  method.     Samples  taken  fro)n  five 
fields  on  Fargo  silt  loam. 


Depth 
Inches 

Fi« 
Set 
1 

:ld   I 

Set 

Field 
Set 

1 

1  II 

Set 

2 

1. 

Field 
Set 
1 

Kansan, 

III 
Set 

2 

Field 
Set 

1 

IV 

Set 
2 

Field 
Set 

1 

V 

Set 
2 

1-  6 

7—12 

13—24 

25—36 

neut. 
acid 
neut. 
neut. 

neut. 
acid 
neut. 
neut. 

neut. 
neut. 
neut. 

neut. 
neut. 
neut. 
neut. 

neut. 
acid 
neut. 
neut. 

acid 
acid 
acid 
acid 

neut. 
neut. 
neut. 

neut. 

neut. 
neut. 
neut. 

neut. 

neut. 
neut. 
neut. 
neut. 

neut. 
neut. 
neut. 
neut. 

2. 

Late  Wisconsin. 

1—  6 

7—12 

13—24 

25—36 

neut. 
neut. 
neut. 
neut. 

neut. 
neut. 
neut. 
neut. 

acid 
acid 
neut. 
neut. 

acid 
acid 
acid 
neut. 

acid 
acid 
acid 
acid 

acid 
acid 
acid 
acid 

acid 
acid 
acid 
neut. 

acid 
acid 

neut. 
neut. 

acid 
acid 
acid 
neut. 

acid 
neut. 
acid 
neut. 

Carrington  Loam.  On  the  Kansan  (Table  27)  every  sample  re- 
acted acid,  while  on  the  Late  Wisconsin  all  were  acid  with  the  excep- 
tion of  the  surface  foot  in  three  sets. 


^^5 

Table  27. — Acidity  hy  the  litmus  method.     Samples  taken  from  five  fields  on 
Carrington  loam. 


Depth 
Inches 

Field   I 

Set          Set 

1               2 

Field 
Set 

1 

11 
Set 

2 

KieM 
Set 
1 

III 

Field 
Set 

1 

(V 

Set 

Field 
Set 

1 

V 

Set 

1. 

Kan  SAN. 

1—  6 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

7—12 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

neut. 

acid 

acid 

13—24 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

25—36 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

2. 

Late  Wiscon 

SIN. 

1—  6 

neut. 

neut. 

acid 

acid 

acid 

neut. 

acid 

neut. 

acid 

acid 

7—12 

acid 

neut 

acid 

acid 

acid 

acid 

acid 

neut. 

acid 

acid 

13—24 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

25-36 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

acid 

Marshall  Silt  Loam.  All  the  samples  on  this  type  (Table  28)  were 
acid  with  the  exception  of  the  second  and  third  foot-sections  of  Set  T 
from  Field  IT. 


Table 
Marshall 

•  28.— Acidity  I 
silt  loam. 

'ry    the   lit 

mits  ; 

method. 

So  III  pi 

cs  taken  from 

five  fie 

Ids  0 

Depth 
Inches 

Field  I 
Set          Set 

1               2 

Field 
Set 

1 

II 

Set 
2 

Field 
Set 

1 

III 

Set 
2 

Field 
Set 
1 

IV 

Set 

2 

Field 
Set 
1 

[  V 
Set 
2 

1—  6 

7-12 

13—24 

25—36 

acid 
acid 
acid 
acid 

acid 
acid 
acid 
acid 

acid 
acid 
neut. 
neut. 

acid 
acid 
acid 
acid 

acid 
acid 
acid 
acid 

acid 
acid 
acid 
acid 

acid 
acid 
acid 
acid 

acid 
acid 
acid 
acid 

neut. 
acid 
acid 
acid 

acid 
acid 
acid 
acid 

Discussion.  The  reaction  toward  litmus  shows  the  soils  of  the 
two  Carrington  series  on  the  Kansan  to  be  more  acid  than  those  on  the 
Late  Wisconsin,  while  with  the  Fars^o  silt  loam  the  opposite  is  true. 
The  samples  of  Marshall  silt  loam  were  practically  all  acid. 

3.     Reaction  as  Determined  by  the  Truog  Method. 


The  reaction  of  the  two  sets  of  samples  from  each  field  was  also 
tested  by  the  Truog  (30)  method.  This  method  is  briefly  as  follows: 
To  10  grams  of  soil  are  added  1  gram  calcium  chloride.  0.1  gm.  zinc 
sulfide  and  100  c.c  water.  The  mixture  is  thoroughly  shaken,  heated 
to  boiling  and  after  boiling  one  minute  a  strip  of  lead  acetate  paper  is 
placed  over  the  mouth  of  the  flask  and  the  boiling  continued  two  min- 
utes longer,  when  the  paper  is  removed.  If  the  soil  is  acid  the  paper 
will  be  darkened  on  the  under  side  in  proportion  to  the  degree  of 
acidity. 

The  results  obtained  by  this  method  are  reported  in  tables  29  to 
32,  and  since  they  so  closely  resemble  those  secured  by  the  litmus 
method  need  no  further  discussion.  A  comparison  of  the  indications 
obtained  by  the  two  methods  is  given  below. 


36 

Table  29. — .Icidity   of  Carrington  silt  loam  soil  as  indicated  by   the   Truog 
method. 


F 

•ield   I 

F 

ield  II 

Field  III 

Field 

IV 

iMcl 

(1  V 

Depth 

Set 

Set 

Set 

Set 

Set           Set 

Set 

Set 

Set 

Set 

Inches 

1 

- 

1 

2 

1               2 

Kansan. 

1 

1 

1—  6 

med. 

med. 

med. 

str. 

med.      mod. 

str. 

nicd. 

med. 

med. 

7—12 

med. 

si. 

med. 

med. 

med.      med. 

str. 

med. 

med. 

.si. 

13—24 

V.  str. 

med. 

med. 

med. 

str.         str. 

V.  str. 

V.  str. 

str. 

str. 

25—36 

med. 

V.  si. 

si. 

med. 

si.          med. 

med. 

str. 

si. 

med. 

2. 

Late  Wisconsin. 

1—  6 

si. 

med. 

si. 

v.sl. 

si.          med. 

med. 

uu'd. 

med. 

med. 

7—12 

med. 

si. 

V.  si. 

v.sl. 

si.          med. 

med. 

si. 

si. 

si. 

13—24 

v.sl. 

si. 

V.  si. 

neut. 

neut.     med. 

si. 

si. 

V.  si. 

si. 

25-36 

si. 

neut. 

neut. 

neut. 

neut.     si. 

V.  si. 

V.  si. 

v.sl. 

neut. 

neut.    =   neutral;    v.    si.    =    very    slight;    si. 
str.  ^  very  strong. 


light;    med.    =:   medium;    str.    =   strong; 


Table  jo. — Acidity  of  Fargo  silt  loam  soil  as  indicated  by  the  Truog  method. 
Field  I  Field  II  Field  III  Field  IV  Field  V 


Depth 

Set 

Set 

Set 

Set 

Set 

Set 

Set 

Set 

Set 

Set 

Inches 

1 

2 

1 

2 

1 

2 

1 

2 

1 

2 

1. 

Kansan. 

1—  6 

sl. 

sl. 

neut. 

neut. 

si. 

med. 

neut. 

neut. 

neut. 

neut. 

7—12 

sl. 

V.  sl. 

neut. 

neut. 

V.  sl. 

med. 

neut. 

neut. 

neut. 

neut. 

13-24 

neut. 

neut. 

neut. 

neut. 

neut. 

sl. 

neut. 

neut. 

neut. 

neut. 

25—36 

neut. 

neut. 

neut. 

neut. 

neut. 

V.  sl. 

neut. 

neut. 

neut. 

neut. 

2, 

Late  Wisconsin. 

1—  6 

neut. 

neut. 

med. 

med. 

med. 

med. 

sl. 

sl. 

sl. 

V.  sl. 

7—12 

neut. 

neut. 

v.sl. 

med. 

sl. 

V.  sl. 

sl. 

V.  sl. 

sl. 

V.sl. 

13—24 

neut. 

neut. 

neut. 

V.  sl. 

V.  sl. 

neut. 

V.  sl. 

neut. 

V.  sl. 

neut. 

25—36 

neut. 

neut. 

neut. 

neut. 

neut. 

neut. 

neut. 

neut. 

neut. 

neut. 

Table  31. — Acidity  of  Carrington  loam  soil  as  indicated  by  the  Truog  method. 


Fi 

i.-ld  I 

Field  II                Field  III 

Field 

1  IV 

Fi« 

:ld  V 

Depth 

Set 

Set 

Set          Set           Set 

Set 

Set 

Set 

Set 

Set 

Inches 

1 

2 

1               2               1 

2 

1 

2 

1 

2 

1.     Kansan. 

1—  6 

sl. 

Str. 

Str. 

str.        str. 

Str. 

Str. 

Str. 

med. 

med. 

7—12 

sl. 

str. 

Str. 

str.        med. 

med. 

med. 

str. 

med. 

str. 

13—24 

v.sl. 

med. 

str. 

med.      str. 

str. 

med. 

med. 

str. 

V.  str. 

25—36 

v.sl. 

sl. 

v.sl 

V.  sl.       V.  sl. 

str. 

sl. 

V.  sl. 

med. 

str. 

2.     Late  Wisconsin. 

1—  6 

sl. 

V.  sl. 

sl. 

sl.          med. 

med. 

sl. 

V.  sl. 

str. 

med. 

7—12 

sl. 

V.  sl. 

sl. 

sl.          str. 

med. 

sl. 

V.  sl. 

med. 

sl. 

13—24 

med. 

sl. 

sl. 

sl.           str. 

str. 

sl. 

V.  sl. 

med. 

sl. 

25—36 

str. 

sl. 

sl. 

sl.          med. 

sl. 

V.  sl. 

neut. 

sl. 

sl. 

Table  32. — Acidity  of  Marshall  silt  loam  soil  as  indicated  by  the  Truog  method. 


Depth 
Inches 

Field  I 

Set           Set 

1               2 

Field  II               Field  III 

Set          Set           Set          Set 

12               12 

Field 
Set 

1 

IV 

Set 

2 

Fie 

Set 

1 

Id  V 
Set 
2 

ICansan. 

1—  6 
7—12 

13—24 
25—36 

str.        med. 
str.        str. 
str.        med. 
med.      V.  sl. 

V.sl. 
V.  sl. 
neut. 
neut. 

str.        V.  str.    str. 
med.     V.  str.    str. 
med.      V.  str.    v.  str. 
sl.          V.  str.    str. 

med. 
V.  sl. 
med. 
med. 

med. 
sl. 

med. 
V.  sl. 

med. 
med. 
str. 
med. 

str. 
med. 
med. 
sl. 

37 


4.  Coloration  of  Ammonia  Solution. 

The  intensity  of  coloration  of  the  aiunionia  extract  as  an  indica- 
tion of  the  dej^ree  of  acidity  (33)  was  tested  on  only  the  two  upper 
sections,  the  smaller  amounts  of  orji;anic  matter  ])resent  in  the  two 
lower  sections  precludino-  the  use  of  this  method.  Twenty  grams  ol 
air-dry  soil  was  treated  with  250  c.c  of  4  per  cent  ammonia,  weU 
shaken  and  allowed  to  stand  for  ei,e:ht  days,  when  portions  were  drawn 
off  and  compared  with  a  standard  solution  in  a  colorimeter.  The 
standard  solution  was  made  up  from  one  of  the  soil  extracts  which 
had  been  drawn  off  from  what  appeared  to  he  the  darkest  in  the  series. 
A  column  of  this  solution  11.7  cm.  high  shut  out  all  the  lig^ht  coming- 
through  an  aperture  1  cm.  in  diameter  from  a  new  25-\vatt  Mazda 
lamp  when  tested  in  a  dark  room.  The  standard  was  made  by  diluting 
100  cc.  of  this  solution  to  F^O  cc.  with  distilled  water.  In  comj)aring 
the  test  solutions  with  the  standard  a  column  of  the  former  10  cm.  in 
height  was  employed  and  the  data  reported  in  tal)les  33  and  34  are  the 
heiglits  in  centimeters  of  columns  of  standard  retjuired  to  exactlv 
equalize  this.  All  solutions  were  brown  in  color,  there  being  none  of 
the  black  color  often  obtained  in  the  determination  of  humus  {maticrc 
noire  of  Grandeau  ). 

On  the  second  day  after  starting  the  extraction  eight  of  the  solu- 
tions, ranging  in  color  from  dark  to  light,  and  representing  the  differ- 
ent types,  were  selected  and  comparisons  with  the  standard  were  made 
daily  in  order  to  determine  when  the  increase  in  depth  of  color  ceased. 
The  results  are  shown  in  table  33.    Thus,  at  the  time  of  reading  on  the 

Tabic  JJ. — Prof^ortioiial  niiioiiiits   of  coloring   matter  cxtrnctcd  by  amniouia 
fro)ii  day  to  day. 


Time  of 

extraction 

Kail! 

^an 

I. ate   Wisconsin 

days 

1 

2 

3 

4 

1 

-'                      3 

2 

10 

,s 

2 

9 

3 

9 

5                     4 

4 

U 

12 

11 

6                     5 

5 

14 

13 

3 

1 

11 

6               5 

6 

16 

14 

3 

2 

12 

6                5 

7 

17 

14 

3 

2 

12 

7               5 

8 

19 

16 

4 

2 

14 

7               7 

sixth  da\-  it  re((uired  a  higher  colunm  of  standard  icj  match  the  dei)th 
of  color  in  Xos.  1 .  2  and  4  on  the  Kansan  and  No.  1  on  the  Late  Wis- 
consin than  it  had  on  the  previous  day,  while  in  Xo.  3  on  the  Kansan. 
and  Xos.  2,  3  and  4  on  the  Late  Wisconsin  the  test  showed  that  no  more 
coloring  matter  had  been  extracted  during  this  period.  During  the 
seventh  dav  but  little  increase  in  the  depth  of  color  occurred.  Then  all 
solutions  were  shaken  and  on  the  next  day  they  were  compared  with 
the  standard.  The  eight  test  solutions  .showed  a  slight  increase  in  the 
depth  of  color  over  the  previous  day.  imdoubtcdly  due  to  the  last 
shaking. 


38 


bo— 


,0        ^^        00        CO  O'^        O        ^Oro 


-T'^        ON        (MiM        I^  -*"^        0\ 


("O  — '        CM        (^  O 


-^■—1         (M         00<~^         "^  ""Oro         00         t  in         O  Cvl'O         O 


<MO        ^^        TiO        Ch  roO        r->        0\rO         O  -f";J-        00        (MO        C\  ^hvo        OC 


LO-— I        "^        "^(^        O  LO"— '        ro        0C<~O        10  roCNl        t^        I^LO        ■— '  fO^O        O 


I'nCN)         "^         ^•-r^         00  COO         Cn         'OCM         "T  "^-r         OC         .— .rs) 


V"        *'  ,— 1  ,— I         , — I 


XCM        to        00        OC  OOC^I        O        ^<M        ^  r-HLD        00        1^^         -t-  OvO        -^ 


MDro        ^        CnCO        00  (^00        CO        t^CM        1"  loro        Ov        unro        0\  f^J^        O 


00 '^      vo  c^  ■*      00      0\  00      00  ^ --H      00      ooa\      ro  o\<-o      >— • 


^T3 1;  r^jOO        0►70^^0        t^<        -rl-iO        ON"OM^        00^        ro. 


w 


^^ 


O    "(MO 


(^  Tf      o^-l  CO  •-- 


CM 


CM 


u 


s!5c«  ^'~'      "^  -^ 


^ 


•->  fM        "— '        l^  10        O 


O         tv.^         -^^         ^CM         ^ 


t^  "-H        ■*  OS  •^"        '-^        O  ^^        to  mCM        <^ 


(VI  00        O        fV]  00        O  00  '^        ■— '        f^  •-->        (^l  rsi  O        0\        OC  '■■O 


,  00        O        rv]  r^        C\  l^  -f        O        r^  ^        Cvl  \o  ON        C^l        t^  ^        "^  CM  CM        «^ 


s)  On        ■— '        rv)  On        O 


CM         r^  •—(         CM  00"*         ^         O  to         1^  io>— '         '^ 


M    •  ■     ■  bi) 

OCMuCM        OCMuOJ 


bo    •         •     •  bfl 


u 
M 

0 

oc: 


<'^ 


,<X       X\l<^  J.r^<i<       ^rl<^  i.^<- 


IM.A'IK    \ 


Illustrating  Character  of  Vegetation  on  C'akkington  Loam. 

1.  Field  V — on  the  Kansan,  the  portion  with  the  trees  still  standing. 

2.  In  the  midst  of  field  IV — on  the  I^te  Wisconsin,  showing  the  cover  of 
leaves  on  the  forest  floor. 


39 


5.  Comparison  of  Indications  Obtained  by  Different  Methods. 


Coml>arisoii  of  Iiidicatiois  Obtained  By  '/ruo^'  and  Litnins 
Methods.  There  is  a  qreat  similarity  between  the  indications  obtained 
by  the  Tniog-  and  the  htmus  methods  as  carried  out  in  the  present  study. 
For  the  most  part,  the  reactions  are  the  same  if.  in  the  Truo.c:  test,  we 
indicate  any  dej^ree  of  acidity  simply  "acid."  The  discrepancies  are, 
in  the  main,  between  samples  which  show  only  a  slight  acidity  by  the 
Truog  method,  most  of  these  l)eini4-  neutral  to  litmus. 

It  might  be  mentioned  here  that  it  so  hai)i)ene(l  that  the  tests  with 
litmus  were  made  after  the  soils  had  been  arranged  in  order  of  their 
color  (p.  58)  so  that  soils  from  the  different  sets,  fields,  types  and 
drifts  were  promiscuously  intermingled,  and  it  was  only  after  the 
reaction  had  been  determined  and  recx>rded  and  the  data  reassembled 
tliat  the  first  intimation  of  the  relation  of  reaction  to  type  and  drift 
was  obtained. 

Comparison  of  Reaction  By  flic  Truoi!^  Method  and  the  Carbonate 
Content.  A  relation  between  the  degree  of  acidity  shown  by  Truog's 
test  and  the  carbonate  content,  as  shown  by  the  percentage  of  carbon 
dioxide  (Tables  21  to  23).  may  be  pointed  out.  \\'here  the  content  of 
carbon  dioxide  is  above  0.11  per  cent  no  acidity  is  shown.  In  the  case 
of  surface  soils  there  seems  to  be  no  doubt  but  that  some  organic 
matter  is  decomposed  during  the  course  of  the  carbon  dioxide  determi- 
nation with  the  evolution  of  carbon  dioxide  and  the  percentage  thus 
raised  slightly.  Hence,  it  appears  safe  to  assume  that  the  showing  of 
even  a  very  slight  acidity  Iw  the  Truog  test  indicates  that  carbonates  in 
any  form  are  either  lacking  or  present  in  so  small  an  amount  as  to  be 
of  no  consequence. 

Coniparison  of  Reaction  By  Litmus  Method  zvith  the  Carbonate 
Content.  Since  the  indications  attained  by  the  litmus  method  agree  so 
well  with  those  obtained  by  the  Truog  test,  the  same  general  agreement 
between  the  reaction  shown  by  it  and  the  carbonate  content  would  be 
expected,  and  this  is  found  to  be  true. 

Comparison  of  Indications  Furnished  By  the  Litmus.  Truoi:;  and 
.immonia  Methods.  The  results  obtained  b}-  the  ammonia  method 
agree  only  in  a  very  general  way  with  those  found  by  the  Truog  and 
Htmus  methods.  Between  the  degree  of  acidity  from  field  to  field  as 
shown  by  the  ammonia  method,  on  one  hand,  and  the  Truog  and  litmus 
methods  on  the  other,  there  is  no  relation.  Nor  does  it  appear  possible 
to  select  any  arbitrary  number  of  units  of  color  in  the  first  corre- 
sponding with  any  particular  decree  of  acidity  as  established  by  the 
second. 


40 
6.     Relation  of  Calcareousness  to  Texture. 

The  variation  in  texture  of  the  samples  from  the  four  types  used 
in  this  study,  as  expressed  by  the  moisture  equivalents  (Table  20). 
varies  rather  widely,  the  highest  average  for  a  type  being  32.2  and  the 
lowest  21.0.  Each  type  was  found  to  have  practically  the  same  texture 
on  both  drifts. 

One  relation  between  the  texture  and  calcareousness  should  be 
pointed  out.  The  Fargo  silt  loam,  which  on  both  drifts  has  the  fines! 
texture,  still  has  carljonate  in  the  surface  six  inches.  The  Carrington 
silt  loam,  next  finest  in  texture,  still  has  carbonate  present  in  the  second 
and  third  foot-sections  on  the  Late  Wisconsin.  l)Ut  none  on  the  Kansan, 
while  the  Carrington  loam,  which  has  the  coarsest  texture  of  all  the 
type  studied,  shows  no  carbonate  in  the  first  three  feet  on  either  drift, 
the  leaching  having  carried  it  below  this  level  even  on  the  more  recent 
formation.  However,  it  should  be  borne  in  mind  that  the  first-named 
type  has  the  most  imperfectly  developed  natural  surface  drainage  and 
the  last  the  best,  the  Carrington  silt  loam  occupying  an  intermediate 
position. 

7.     Relation  of  Calcerousness  to  Age  of  Drift. 

As  pointed  out  above  the  texture  of  the  soil  on  each  of  the  three 
types  is  quite  uniform  from  drift  to  drift.  So,  any  difference  in  the 
amount  of  calcium  carbonate  between  soils  from  any  one  type  on  the 
two  drifts  must  be  due,  not  to  difference  in  texture  and  hence  to  differ- 
ences in  the  rate  of  percolation,  but  to  the  age  of  the  drift.  In  the 
samples  from  the  Fargo  silt  loam  carbonate  is  found  on  both  drifts  and 
no  difference  in  the  degree  of  leaching  is  shown.  On  the  Carrington 
loam  the  carbonate  has  been  leached  out  of  the  first  three  feet  on  both 
drifts,  so  that  it  is  only  in  the  soils  from  the  Carrington  silt  loam  that 
any  relation  between  the  calcareousness  of  the  soil  and  the  age  of  the 
drift  will  be  apparent.  In  the  soils  from  this  type  on  the  Kansan  no 
carbonate  is  found  above  the  three  foot  level  but  in  the  majority  of 
fields  on  the  Late  Wisconsin  it  occurs  in  the  third  foot-section  and  in 
some  instances  in  the  second,  indicating  that  leaching  has  proceeded 
farther  on  the  Kansan. 


-11 


c.  inokganic  constituents. 


1.   Methoiis  of  Chemical  Analysis. 

The  drift  samples  froin  the  three  glacial  types  were  subjected  to  a 
complete  or  rock  anal\sis.  In  the  case  of  the  individual  field  samples, 
determinations  of  only  carbon  dioxide  and  i)hosphoric  acid  were  made. 

The  methods  of  analysis  employed  were  those  used  in  the  labora- 
tory of  the  United  States  Geological  Survey  (19)  except  in  the  case  of 
phosphoric  acid.  In  determining  this  extremely  important  constituent 
by  the  method  used  in  that  laboratory  such  discordant  results  were 
obtained  that  the  main  investigation  was  halted  until  a  satisfactory 
method  for  the  determination  of  total  phosphoric  acid  could  be  devel- 
oped. The  author  (28)  has  already  published  an  account  of  this  sub- 
sidiary investigation. 

The  method  for  the  determination  of  phosphoric  acid  thus  dexel- 
oped  is  briefly  as  follows :  One  gram  of  dry  soil  is  weighed  into  a  ])lat- 
inum  dish  of  appropriate  size  and  ignited  in  the  muffle  at  dull  red  heat 
a  sufficient  length  of  time  to  insure  the  com]^lete  oxidation  of  the 
organic  matter.  After  cooling,  10  cc.  of  distilled  water,  10  cc.  of  nitric 
acid  and  5  cc.  of  hydrofluoric  acid  are  added,  the  mixture  well  stirred, 
and  the  contents  of  the  dish  evaporated  on  the  steam  bath  until  ai)proxi- 
mately  5  cc.  remain,  when  an  additional  5  cc.  of  hydrofluoric  acid  are 
added,  the  mixture  again  well  stirred,  and  the  evaporation  continued  to 
complete  dryness.  Evaporation  with  small  quantities  of  nitric  acid  is 
repeated  two  or  three  times.  After  the  final  evaporation  the  residue  is 
dried  at  110  degrees  C.  in  the  air-bath  for  an  hour  or  two  in  order,  as 
Washington  (32,  p.  163)  states,  "to  render  insolul)le  any  silica  which 
might  otherwise  come  down  with  the  phosphorus."  When  cool  the 
residue  is  taken  up  with  3  cc.  of  concentrated  nitric  acid  and  7  cc.  of 
distilled  water,  boiled  gently  for  a  few  minutes,  and  after  cooling 
somewhat,  is  filtered  and  washed  :  the  phosphorus  in  the  filtrate  is  pre- 
cipitated with  ammonium  molybdate.  and  finally  weighed  as  magnesium 
pyrophosphate.  With  soils  poor  in  phosphorus  a  larger  sample  of  soil 
should  be  taken  and  the  amounts  of  the  reagents  ])roportionately 
increased. 

It  w'as  later  ascertained  tliat  it  about  1.^  cc.  of  boiling  hot  water  be 
added  after  treating  the  residue  with  3  cc.  of  nitric  acid  and  the  con- 
tents of  the  dish  stirred  and  set  aside  for  5  or  10  minutes,  instead  of 
bringing  this  to  lioiling.  the  time  of  filtering  could  be  considerably 
shortened  without  lessening  the  accuracy  of  the  method. 


42 

The  general  scheme  for  the  determination  of  the  other  inory^anic 
constituents  is  l)riefly  outHned  in  the  following^  sentences:  One  crram 
of  dry  soil  was  weiohed  into  a  25  cc.  platinum  crucihle  and  ignited  in 
the  nuififle  at  a  dull  red  heat  for  a  sufficient  leng-th  of  time  to  destroy  all 
organic  matter,  when  it  \vas  remoxed,  cooled  and  weighed.  The  dif- 
ference between  this  and  the  original  weisrht  gives  the  %'olatile  matter. 

The  ignited  soil  was  then  fused  with  five  grams  of  sodium  carbon- 
ate and  the  melt  digested  some  time  with  hot  water,  acidified  with 
hydrochloric  acid  and  finally  evaporated  to  dryness.  This  was  ex- 
tracted with  warm  dilute  hydrocloric  acid  and  the  residue  filtered  ofT. 
dried,  ignited  and  weighed.  It  was  then  treated  with  hydrofluoric  acid, 
evaporated  to  dryness,  ignited  and  again  wei^rhed.  the  difference  be- 
tween the  two  weights  giving  the  amount  of  silica. 

In  the  filtrate  the  ses(|uioxi(les  of  iron,  aluminum,  phos])horus  and 
titanium  were  precipitated  with  ammonia,  filtered  off,  ]:)laced  in  the 
same  crucil)le  with  traces  of  these  left  from  the  silica,  dried,  ignited  anrl 
weighed.  The  combined  oxides  were  fused  with  potassium  pyrosul- 
phate,  the  melt  dissolved  in  water  to  which  a  few  cubic  centimeters  of 
sulphuric  acid  had  been  added,  filtered,  and  the  residue  ignited,  wei'^fhed 
and  evaporated  with  hydrofluoric  acid.  It  was  then  ignited  and  arain 
weighed,  the  loss  in  weight  representing  a  last  trace  of  silica  included 
in  the  comljined  oxides,  this  being  added  to  the  amount  first  obtained. 

In  the  filtrate  from  the  pyrosulphate  fusion  the  iron  was  reduced 
with  hydrogen  sulphide  and  titrated  with  permanganate  and  the  tita- 
nium  determined  colorimetricallv  in  this  solution  after  the  faint  per- 
manganate tint  had  disappeared.  The  phosphorus  was  determined  in 
a  separate  sample  as  described  above.  When  the  amounts  of  iron, 
titanium  and  phosphorus  were  deducted  from  the  amount  of  combined 
oxides  the  quantity  of  aliiiiiiiia  was  obtained. 

In  the  filtrate  from  the  sesquioxide  precipitation,  the  lime  was 
thrown  down  with  ammonium  oxalate  and  subsequently  determined  by 
titration  with  permanganate. 

The  uiagiicsia  was  precipitated  in  the  filtrate  after  the  removal  of 
the  lime  and  finally  weighed  as  magnesium  pyrophosphate. 

The  potash  and  soda  were  determined  bv  the  Lawrence  Smith 
method  (20). 

The  anah  tical  data  are  the  averages  of  concordant  duplicate  deter- 
minations. 

The  inorganic  constituents  in  the  \arious  soil  types  on  the  differ- 
ent drifts  are  shown  in  tables  35  to  37.  To  make  evident  the  variation-^ 
in  individual  constituents  these  are  dealt  with  separately  in  later  tables. 


43 

Table  3j. — Composition   oj  Carringion  silt  loam. 

1—6  7—12  U— -M 

inches  inches  inches 

percent  per  cent  perKiil 

1.     Kansan. 

SiOj  69.59  71.02  72.45 

AI0O3  11.09  11.35  11.% 

FeoO:{    3.55  3.81  4.40 

MgO    0.81  0.84  O.S.^ 

CaO    1.13  1.14  1.02 

XajO  1.20  1.36  1.37 

K2O   1.76  1.84  1.90 

TiO-    0.64  0.64  O.M 

Pi.O.-.    0.23  0.20  0.15 

CO-    0  08  0.0-'  {).()<, 

\'olatilc   matter    10.52  8.58  6.07 

2.     Lativ  Wiscon.'^ix. 

SiO::  72.89  73.62  75.24 

AI2O:!   10.46  10.87  1 1.35 

Fe203    2.99  3.21  3.42 

MgO    0.72  0.74  0.88 

CaO    1.24  1.18  124 

Xa-.O  139  135  1.33 

K2O  1.66  1.74  1.86 

TiOo    0.50  0.52  0.54 

P20.r;    0.18  0.17  0.14 

COo   0.07  0.05  0.13 

\'c  .latilc  matter    9.38  7.80  5.34 

Table  j6. — Composition  of  Forgo  silt  loam. 

1—6  7— IJ  13 — 24 

inches  inches  inches 

l)er  cent  per  cent  per  cent 

1.     Kaxsan. 

SiOo  59.05  65  81  71.71 

AUb-,.   10.29  11.46  12.43 

FeoO.-?   3.37  3.79  4.21 

MgO    1.02  1.06  1.21 

CaO   2.34  2.08  1.55 

Na-.0   1.31  1.48  1.45 

KoO  1.57  1.64  1.83 

TiOo , 0.60  0.66  0.73 

P.,05    0.31  0  24  0.19 

002   0.30  0.20  0.06 

Volatile  matter    20.34  12.12  5.41 

2.     [,.\TK  Wisconsin. 

SiO-.  68.08  70.42  72.02 

AUb-x    10.18  10.62  11.57 

FeoO ;    3.21  3.21  3.68 

MgO    1.07  1.08  1.23 

CaO   1.97  1.84  1.86 

XaoO   1.18  1.29  1.27 

K-O  1.60  1.68  1.71 

Ti'O-    0.60  0.60  0.()() 

PoOr,    0.23  0.18  0.15 

CO.,   0.49  0,57  0.54 

X'ofatile   matter    11.68  9.61  6.43 


25—36 

.\v.    1-  3(. 

inches 

inches 

|iir  cent 

per  cent 

75.14 

72.63 

11.89 

11.69 

4.78 

4.2'' 

0.93 

0.87 

0.93 

1.03 

1.29 

132 

1.87 

1.86 

0.70 

0.66 

0.13 

0.16 

O.03 

0.06 

3.73 

6.45 

73.65 

74.05 

12.13 

11.38 

3.81 

3.44 

1.21 

0.94 

2.08 

1.51 

1.31 

1.33 

1.87 

1.80 

0.53 

0.53 

0.11 

0.14 

1.06 

0.42 

2.99 

5.64 

25—36 

.\v.   1— .V. 

inches 

inches 

per  cent 

per  cent 

73.41 

69.18 

12.28 

11.86 

4.14 

3.98 

1.49 

1.25 

192 

1.89 

1.59 

1.48 

1.86 

1.76 

0.72 

0.69 

0.18 

0.21 

0.84 

0.38 

2.19 

7.94 

71.97 

71.08 

12  54 

11.50 

3.95 

3.61 

1.51 

1.27 

2.16 

1.97 

1.18 

1.23 

1.75 

1.70 

0.60 

0.60 

0.11 

0.16 

104 

0.70 

4.40 

7.16 

44 


'J  able 


-Composition  of  Carrington  loam. 


SiOa 

AI2O3   

FesOa    ....:... 

AlgO    

CaO  

Na20  

K2O    

TiOo    

P20fi    

CO2 

Volatile  matter 

Si02  

AI2O3    

Fe203    

MgO    

CaO   

NaoO  

KoO  

TiOo    

P20r>    

COj 

Volatile  matter 


1—6 

7—12 

13 — 24 

25—36 

Av.   1—36 

inches 

inches 

inches 

inches 

inches 

l)er  cent 

per  cent 

per  cent 

per  cent 

per  cent 

1. 

Kansan. 

75.69 

77.05 

74.95 

78.23 

76.52 

9.50 

10.54 

12.01 

10.46 

10.83 

2.93 

3.41 

4.23* 

4.04 

3.81 

0.70 

0.71 

0.94 

0.78 

0.81 

1.06 

0.92 

0.97 

1.02 

0.99 

1.46 

1.42 

1.38 

1.41 

1.41 

1.72 

1.76 

1.82 

1.65 

1.74 

0.68 

0.73 

0.69 

0.60 

0.67 

0.23 

0.18 

0.18 

0.15 

0.18 

0.09 

0.04 

0.03 

0.04 

006 

6.41 

3.73 

3.32 

2.66 

3.68 

2.     Lat 

E  Wisconsin. 

76.34 

77.37 

76.26 

76.98 

76.70 

9.52 

10.66 

11.81 

11.77 

11.22 

2.82 

3.32 

3.93 

3.96 

3.65 

0.60 

0.67 

0.84 

0.85 

0.77 

1.09 

0.97 

0.95 

1.07 

1.02 

1.41 

1.42 

1.40 

1.42 

1.41 

1.86 

1.99 

1.96 

1.76 

1.88 

0.60 

0.60 

0.58 

0.58 

0.59 

0.19 

0.15 

0:14 

0.14 

0.15 

0.10 

0.06 

0.05 

0.04 

0.06 

6.71 

4.15 

3.77 

2.89 

4.03 

2. 

Silica. 

The  silica  (Table  3S)  is  quite  uniformly  distributed  on  the  two 
drifts,  the  amounts  differing  slightly,  however,  from  type  to  type.  The 
lowest  averages  are  those  for  the  Fargo  silt  loam  and  the  highest  those 
for  the  Carrington  loam.  On  the  Kansan,  the  former,  in  the  first  6-inch 
section,  shows  only  59.05  per  cent,  but  this  does  not  appear  so  strange 
when  we  take  into  consideration  the  fact  that  this  soil  carries  over  20 
per  cent  of  volatile  matter.  On  the  Kansan,  the  maximum  appears  in 
the  lowest  section,  while  on  the  Late  Wisconsin  it  is  reached  in  the 
second  foot  or  the  lower  half  of  the  first.  The  soils  on  the  youngei 
drift  are,  on  the  average,  somewhat  richer  in  silica  and  the  maximum 
amount  is  found  at  a  higher  level. 


Depth 
Inches 

1—  6 

7—12 

13—24 

25—36 

Averaa 

1—36 


Tabic  38. — Silica  in  the  different  sections. 


Carrington  s;!t  loam  Fargo  silt  loam  Carrington  loam 

Kansan  Late  Wis.  Kansan  l.ate  Wis.  Kansan  Late  Wis. 

per  cent  per  cent  per  cent  per  cent  per  cent  per  cent 


69.59 

72.89 

59.05 

71.02 

73.62 

65.81 

72.45 

75.24 

71.71 

75.14 

73.65 

73.41 

72.b3 


74.05 


69.18 


68.08 
70.42 
72.02 
71.97 

71.08 


75.69 
77.05 
74.95 
78.23 

76.52 


76.34 
77.37 
76.26 
76.08 

76.70 


45 

3.  Iron. 

The  iron  is  reported  as  ferric  oxide  in  table  3*^.  The  distribution 
is  quite  uniform  from  type  to  tyjie  and  from  drift  to  drift.  On  the 
Kansan,  all  three  types  show  a  his/her  content  than  on  the  Late  Wiscon- 
sin, and,  on  the  latter,  the  averap^e  percentai::es  are  almost  identical. 
The  difference  between  drifts  is  c^reatest  on  the  Carrinqton  silt  loam 
where,  in  the  second  and  third  foot-sections,  it  amounts  to  1.0  per  cent, 
and  least  on  the  Carrington  loam,  which  exhibits  a  remarkable  parallel 
ism  also  in  the  case  of  practically  all  other  constituents.  On  the 
Kansan,  the  maximum  on  two  of  the  three  types  is  shown  in  the  second 
foot-section,  while  on  the  T.ate  Wisconsin  it  is  found  in  the  third  foot. 

Table  39. — Ferric  oxide  in  the  different  sections. 


Depth 
Inches 

Carrington 
Kansan 
per  cent 

silt  loam 
l.ate  Wis. 
per  cent 

Fargo 
Kansan 
per  cent 

silt  loam 
Late  Wis. 
per  cent 

Carrington  loam 
Kansan           Late  Wis. 
per  cent            per  cent 

1—  6 

3.55 

2.99 

3.37 

3.21 

2.93 

2.82 

7—12 

3.81 

3.21 

3.79 

3.21 

3.41 

3.32 

13—24 

4.40 

3.42 

4.21 

3.68 

4.23 

3.93 

25-36 

4.78 

3.81 

4.14 

3.95 

4.04 

3.96 

Average 
1—36 

4.29 

3.44 

3.98 

3.61 

3.81 

3.65 

4.  Alumina. 

The  total  alumina  (Table  40)  is  very  uniformly  distributed  on  the 
two  drifts  as  well  as  from  type  to  type,  on  the  Kansan  showing  a  mini- 
mum of  9.50  per  cent  and  a  maximum  of  12.43  per  cent  and,  on  the  Late 
\\'isconsin.  a  rancfe  from  ^\52  to  12.54  per  cent. 

Table  40. — Alumina  in  the  different  sections. 

Carrington  silt  loani  Fargo  silt  loam  Carrington  loam 

Late  Wis.  Kansan  Late  Wis.  Kansan  Late  Wis. 

per  cent  per  cent  per  cent  per  cent  per  cent 

10.46  10.29  10.18  9  50  9.52 

10.87  11.46  10.62  10.54  10.66 

11.35  12.43  11.57  12.01  11.81 

12.13  12.28  12.54  10.46  11.77 

11.38  11.86  11. .50  10.83  11.22 

In  the  vertical  distribution  the  maximum,  as  in  the  case  of  the 
ferric  oxide,  on  the  Kansan,  is  to  be  found  in  the  second  foot  and  on 
the  Late  Wisconsin  in  the  third  foot,  the  opposite  of  what  was  found 
for  silica.  The  percentat^^es  in  the  upper  sections  are  not  as  large  as 
those  in  the  lower  ones,  which  is  to  be  explained  by  the  downward 
translocation  of  colloidal  clay. 

The  similarity  in  the  alumina  content  on  the  two  drifts  is  evident 
from  the  averages  for  the  three-foot  sections  on  all  three  types,  viz.. 
11.46  per  cent  on  the  Kansan  and  11.37  per  cent  on  the  Late  Wisconsin. 


Depth 
Inches 

Kansar 
per  ceni 

1—  6 

11.09 

7—12 

11.35 

13—24 

11.96 

25—36 

11.89 

Average 
1—36 

11.69 

46 

5.  Titanium. 

The  titanium  (Table  41)  is  very  uniformly  distributed  uu  the  two 
drifts,  and  on  the  three  types  as  well.  The  amounts  found  on  the 
Kansan  are  slightly  higher  in  all  cases  than  those  found  on  the  Late 
W'isconsin.  thus  resembling  the  alumina  in  distribution. 

Tabic  41. — Titanium  in  the  dilTcrcnt  sections. 

Carrington   silt   loam  Fargo   silt   loam  •  Carriiigton   loam 

Depth  Kansan  Late  Wis.  Kansan  Late  Wis.  Kansan  I  ate  Wis. 

Inches  |ier  cent  per  cent  per  cent  ])er  cent  iier  cent  per  cent 

1_  6  0.64  0.50  0.60  0.60  0.68  0.60 

7_12  0.64  0.52  0  66  0.60  0.73  0.60 

13_24  0.64  0.54  0.73  0.60  0.69  0.58 

25—36  0.70  0.53  0.72  0.60  0.60  0.58 

Average 

1_36  0.66  0.53  0.69  0.60  0.67  0.59 

6.  Lime. 

The  total  lime  (Table  42,  part  1)  varies  almost  directly  with  the 
carbon  dioxide.  On  the  Carrington  silt  loam  the  amount  in  the  first 
three  sections  is  practically  the  same  on  both  drifts,  varying  between 
1.0  and  1.25  per  cent.  In  the  third  foot,  however,  the  quantity  on  the 
Late  Wisconsin  is  niore  than  twice  as  great,  reaching  2.08  per  cent,  as 
compared  with  0.93  per  cent  on  the  Kansan. 

On  the  Fargo  silt  loam  there  is  not  a  wide  difference  between  the 
amounts  of  this  constituent  in  the  different  sections  on  either  drift,  and 
the  average  for  the  three  feet  is  1.89  per  cent  in  the  case  of  the  Kansan 
and  1.97  per  cent  in  that  of  the  Late  Wisconsin. 

The  amount  of  lime  in  the  different  sections  of  Carrington  loam  is 
remarkably  similar,  the  dift'erence  between  the  two  drifts  for  any  given 
level  being  no  greater  than  that  between  duplicate  determinations  on 
the  same  sample.  All  calcium  compounds  at  all  readily  soluble  have 
evidently  been  leached  out  of  this  type  to  a  depth  greater  than  three 
feet. 

The  amount  of  lime  in  the  form  of  carbonate  was  computed  from 
the  carbon  dioxide  content  (Table  42,  pt.  2).  On  the  Carrington  silt 
loam,  only  in  the  second  and  third  foot-sections  of  the  Late  Wisconsin 
is  any  appreciable  quantity  shown.  On  the  Fargo  silt  loam  the  second 
foot-section  on  the  Kansan  is  the  only  one  to  show  a  deficiency  in  this, 
while  with  the  Carrington  loam  on  both  drifts  the  carbonate  has  been 
leached  out  to  a  depth  greater  than  three  feet. 

By  deducting  the  lime  as  carbonate  from  the  total  amount  the 
quantity  in  the  form  of  silicate  is  secured  (Table  42,  pt.  3).  On  the 
two  prairie  types,  this  decreases  from  the  surface  downward.  On  the 
forest  type,  the  Carrington  loam,  the  first  and  fourth  sections  show 
like  amounts,  while  the  intervening  two  are  alike  and  show  somewhat 
smaller  amounts. 


47 


I  iihli-  4>.—I.inii-  ill  the  diffrrnil  scclioiis. 


Depth 
Inches 


1—  6 

7—12 

13—24 

25-36 

A  verace 

1—36 


1—  6 

7—12 

13—24 

25—36 

.'\verage 

1—36 


1—  6 

7—12 
13—24 
25-36 
Averasre 

1-36 


CarriiigtDii   silt   loam 
Kansaii  I. ate  Wis. 


I'aiKn    silt    loam 
Kansaii  I. ate  \Vi 

per  cent  per  ceni 

1.      ToTAI.. 


Carrington  loam 
Kansan  Fate  Wis. 


1.13 
1.14 
1.02 

0.93 
1.03 

T.I  M  K 

0.10 
0.10 
0.07 
0.04 

0.07 


1  03 
1.04 
0.95 
0.89 

0.96 


1.24 
1.18 
1.24 
2.08 

1.51 


2.34 
2.08 
1.55 
1.92 

1.80 


1.97 
1.84 
1.86 
2.16 

1.97 


1.06 
0  92 
0.97 
1.02 

0.99 


CARm)X.\TE   (coniputocl   troni  CO::  content.') 


0.10 

0.07 
0.16 
1.36 


0.40 
075 
OOS 
l.Of) 


0.65 
0.6' > 
0  6R 
1 J3 


0.53  0.49  0  89 

3      T.i.\rE  .\s  Silicate. 


1  14 
1.11 
1.08 
0.72 

0.97 


104 
1.83 
1.47 
0.86 

1.27 


132 
1.15 
1.18 
0.83 

1.08 


0.09 
0  07 
0  0/ 
O.(H') 

0.07 


0.97 
0.85 
0.90 
0.96 

0.92 


1.09 
0  97 
0.95 
1.07 

1.02 


•■).'/) 
0  08 
(  05 
ti.07 

0.07 


0.99 
0  89 
0.90 
100 

0.95 


Discussion.  With  one  exception  the  amount  of  total  hme  in  the 
surface  section  is  jjfreater  than  in  the  second.  Plant  roots  feedino-  in 
the  lower  levels  carry  this  constituent  into  the  aerial  parts,  which,  on 
death  and  decay,  leave  behind  in  the  surface  laver  this  translocated  lime. 

On  the  Kansan  the  two  Carrinpton  .series  ha\'e  lost  the  more 
readilv  .soluble  lime  compounds  to  a  denth  of  more  than  three  feet. 
The  Carrinofton  silt  loam  on  the  I-ate  Wisconsin  still  retains  a  consid- 
erable amount  in  the  third  foot-section,  but  with  the  Carrinqton  loam 
the  leachincf  has  been  as  extensive  as  on  the  Kansan. 

The  poorly  drained  condition  of  the  Farg"o  silt  loam  has  prevented 
anv  serious  leaching"  on  this  type.  This  is  well  illustrated  by  tal)le  42. 
part  2.  which  shows  every  section  well  stipplied  with  carbonate  with 
the  exception  of  the  second  foot  on  the  Kansan. 

On  the  Kansan  lime  in  the  form  of  carbonate  has  been  leached  out 
to  a  depth  t^-reater  than  three  feet  with  both  the  Carrinqton  silt  loam 
and  the  Carrington  loam.  On  the  Tate  W^isconsin  the  same  is  true  for 
the  latter  type,  but  there  is  still  an  apprecial)le  rpiantitx  in  the  third 
foot-section  of  the  former. 

On  each  t\pe  the  average  amount  of  lime  as  silicate  is  very  simi- 
lar on  both  drifts  with  the  exception  of  the  Fartjo  silt  loam,  where  it  is 
sliq-htly  the  higher  on  the  Kansan.  There  is  a  general  decrease  in  the 
amount  of  this  from  the  surface  downward  on  the  prairie  types,  while 
on  the  forest  t\'pe  there  is  but  little  variation  in  its  vertical  distribution. 


48 

7.  Magnesia. 

There  is  very  little  difference  between  the  amounts  of  magnesia 
(Table  43)  found  on  the  two  drifts  on  any  given  type.  The  largest 
amount  is  found,  as  in  the  case  of  lime,  on  the  Fargo  silt  loam,  the 
average  being,  respectively,  1.25  per  cent  for  the  Kansan  and  1.27  per 
cent  on  the  Late  Wisconsin.  The  averages  for  the  Carrington  loam  are 
slightly  lower  than  those  for  the  Carrington  silt  loam,  which  are  0.8? 
per  cent  and  0.94  per  cent,  respectively,  for  the  two  drifts. 

Table  43. — Magnesia  in  the  different  scctiotts. 


Depth 

Kansan 

Late  W^is. 

Kansan 

Late  Wis. 

Kansan 

Late  Wis. 

Inches 

per  cent 

per  cent 

per  cent 

per  cent 

per  cent 

per  cent 

1—  6 

0.81 

0.72 

1.02 

1.07 

0.70 

0.60 

7—12 

0  84 

•    0.74 

1.06 

1.08 

0.70 

0.67 

13—24 

0.85 

0.88 

1.21 

1.23 

0.94 

0.84 

25—36 

0.93 

1.21 

1.49 

1.51 

0.78 

0.85 

Average 

1—36 

0.87 

0.94 

1.25 

1.27 

0.81 

0.77 

The  ratio  of  total  lime  to  magnesia  (Tal)le  44,  pt.  1)  falls  between 
1.0  and  1.8,  averaging  1.4  for  the  three-foot  section  on  all  types.  It  is 
very  similar  for  each  type  on  both  drifts,  the  greatest  difference  being 
shown  on  the  Carrington  silt  loam,  where,  on  the  Kansan,  it  is  1.2  as 
compared  with  1.5  on  the  Late  Wisconsin.  The  optimum  ratio  varies 
with  different  plants  (26),  but  in  general  the  lime  must  equal  or  exceed 
the  magnesia  if  the  most  satisfactorv  cultural  results  are  to  be  obtained 
(24,  p." 33). 

Table  44. — Relation  of  lime  to  magnesia  in  the  different  sections. 

Carrington  silt  loam  Fargo  silt  loam  Carringrton  loam 

"  Late  Wis. 

per  cent 


1.8 
1.4 
1.1 
1.3 

1.3 


1.6 
1.3 
1.0 
1.2 

1.2 

On  both  prairie  types  the  ratio  of  the  portion  of  the  lime  in  the 
form  of  silicate  to  magnesia  (Table  44,  pt.  2)  decreases  from  the  sur- 
face downward,  as  was  the  case  with  the  amounts  of  lime  in  the  form 
of  silicate  on  these,  while  on  the  forest  type  it  decreases  through  the 
first  three  sections,  rising  slightly  again  in  the  third  foot.  On  both 
drifts  the  average  ratio  for  each  type  is  very  similar  with  the  exception 
of  the  Fargo  silt  loam,  where  that  for  the  Kansas  is  the  higher. 


Depth 
Inches 

Kansan 
per  cent 

Late  Wis. 
per  cent 

Kansan 
per  cent 

1 

Late  Wis.           Kansan 
per  cent             per  cent 

1.     Ratio  of 

ToT\L  Lime 

TC 

1  M.\gnesia. 

1—  6 
7—12 

13—24 
25—36 

1.4 
1.3 
1.2 
1.0 

1.7 
1.6 
1.4 
1.6 

2.3 
2.0 
1.3 

1.3 

1.8                1.5 
1.7                 1.3 
1.5                 1.0 
1.4                 1.3 

Average 

1—36 

1.2 

1.5 

1.6 

1.6                 1.2 

2. 

R.\TIO  OF  Ll 

ME  AS  Silicate 

TO  Magnesia. 

1—  6 

7—12 

13-24 

25—36 

1.2 
1.2 
1.1 
0.9 

1.5 
1.5 
1.2 
0.6 

1.9 
1.7 
1.2 
0.5 

1.2                 1.4 
1.0                 1.2 
0.9                 1.0 
0.5                 1.2 

Average 
1—36 

1.1 

1.1 

1.2 

0.8                 1.2 

49 

Piscussion.  The  amounts  of  magnesia  found  on  the  two  drifts 
are  very  similar,  the  averages  for  the  three  foot  section  on  the  Kansan 
and  the  Late  Wisconsin,  respectively,  heine;  0.98  per  cent  and  0.99  per 
cent.  Considerahle  variation  from  type  to  ty])e  is  shown,  the  Farp^o 
silt  loam  carrying  the  most  and  the  Carrington  loam  the  least. 

The  ratio  of  total  lime  to  magnesia  is  slightly  the  hig^her  on  the 
Late  Wisconsin,  this  heing  due  to  its  higher  proportion  of  the  former 
constituent. 

'{"he  average  ratio  of  lime  as  silicate  to  magnesia  is  very  similar 
on  both  drifts  with  the  exception  of  that  for  the  Ivargo  silt  loam  on  the 
Late  Wisconsin,  where  it  is  somewhat  the  lower.  The  maximum  ratio 
in  every  instance  is  found  in  the  surface  section  while  the  minimum  is 
found  in  the  third  foot,  except  on  the  Carring:ton  loam,  where  it 
appears  in  the  second  foot-section. 

8,  Phosphoric  Acid. 

The  phosphoric  acid  (Tables  45  to  48)  was  determined  in  all  the 
field  samples  bv  the  modification  of  Washington's  method  described 
above  (p.  41).  Averages  from  these  give  the  data  for  the  drift 
samples  (Table  49). 

Carrington  Silt  Loam.  On  this  type  (Table  45)  there  is  shown, 
in  general,  a  decrease  from  the  surface  downward,  a  distribution  char- 
acteristic of  prairie  soils  (3).  The  amount  found  on  the  Kansan  is 
slightly  higher  than  that  on  the  Late  Wisconsin,  the  general  average 
for  the  former  being  0.165  per  cent  compared  with  0.141  for  the  latter. 
The  distribution  from  field  to  field  is  very  regular. 


Table 

4^. — Phosphoric  acid 

in  the  different 

sections 

from  the  fi-z 

■e  fields  on 

Carrington 

•■  silt  loam. 

Depth 
Inches 

Field 

I 

per  cent 

Field 

II 

per  cent 

Field 
III 

per  cent 

1.     Kans.vn. 

Field 
IV 

per  cent 

Field 
V 

per  cent 

Average  for 

5  fields 

per  cent 

1—  6 

7—12 

13—24 

25—36 

0.245 
0.200 
0.159 
0.140 

0.220 
0.223 
0.165 
0.143 

0.258 
0.220 
0.147 
0.127 

0.214 
0.191 
0.137 
0.102 

0.204 
0.188 
0.147 
0.134 

0.228 
0.204 
0.151 
0.129 

Average 
1—36 

0.174 

0.176 

0.171 

0.147 

0.159 

0.165 

2. 

Late  Wisconsin. 

1—  6 

7—12 

13—24 

25—36 

0.204 
0.210 
0.156 
0.102 

0.182 
0.151 
0.108 
0.104 

0.172 
0.153 
0.144 
0.121 

0.175 
0.172 
0.147 
0.143 

0.178 
0.156 
0.118 
0.096 

0.182 
0.168 
0.135 
0.113 

Average 
1-36 

0.155 

0.126 

0.142 

0.154 

0.127 

0.141 

Fargo  Silt  Loam.  While  somewhat  larger  amounts  of  phosphoric 
acid  are  found  in  the  soils  of  this  type  (Table  46),  the  same  observ^a- 
tions  as  to  its  distribution  apply.  11ie  difiference  in  the  amounts  found 
on  the  two  drifts  are,   however,   much   greater,   the  average   for  the 


50 

Kansan  being  0.214  per  cent  compared  with  0.156  per  cent  for  the  Late 
Wisconiiin.  The  former  shows  the  higher  content  in  all  four  levels.  It 
is  to  be  iioted  that  the  decrease  in  the  amounts  found  in  the  third  foot- 
section  en  the  Kansan  is  not  nearly  so  great  as  on  the  younger  drift. 

TabU  46. — Phosphoric  acid  in  the  different  sections  from  the  five  fields  on 
Fargo  silt  loam. 


Depth 
Inches 

Field 

I 

per  cent 

Field 

II 

per  cent 

Field 

III 

per  cent 

1.     Kansan. 

Field 

IV 

per  cent 

Field 

V 

per  cent 

Average  for 

5  fields 
per  cent 

1—  6 

7—12 

13—24 

25-36 

0.290 

0.248 
0.169 
0.179 

0.223 
0.182 
0.172 

0.255 
0.207 
0.162 
0.168 

0.363 
0.264 
0.207 
0.201 

0.338 
0.283 
0.210 
0.175 

0.311 
0.243 
0.186 
0.179 

Average 
1—36 

0.206 

0.187 

0.240 

0.232 

0.214 

2. 

Late  Wisconsin. 

1—  6 

7—12 

13—24 

25—36 

0.239 
0.185 
0.146 
0.118 

0.229 
0.156 
0.172 
0.099 

0.219 
0.213 
0.188 
0.121 

0.220 
0.179 
0.134 
0.112 

0.216 
0.185 
0.115 
0.111 

0.22.S 
0.184 
0.151 
0.112 

Average 
1—36 

0.159 

0.154 

0.175 

0.148 

0.142 

0.156 

Carrmgton  Loam.  In  the  soils  on  this  type  (Table  47)  neither  the 
distribution  from  the  surface  downward  nor  that  from  field  to  field  is 
as  regular  as  was  the  case  on  the  two  prairie  types.  The  averages  for 
the  five  fields  on  the  two  drifts  show  a  general  decrease  from  the  sur- 
face downward,  although  on  the  Late  Wisconsin  they  are,  below  the 
first  6-inch  section,  practically  the  same.  The  general  average  for  the 
Kansan  is  slightly  the  higher,  being  0.177  per  cent  as  compared  with 
d.l.Sl  per  cent  for  the  Late  Wisconsin. 


TabU'. 
Carringtc  n 

4^. — Phosphoric  acid 
'.  Icam. 

in  the  different 

sections 

from  the  j 

five  fields  on 

Depth 
Inches 

Field 

I 

per  cent 

Field 

II 

]ier  cent 

Field 
III 

per  cent 

1.     Kans.'vn. 

Field 

IV 

per  cent 

Field 
V 

lier  cent 

Average  for 
5  fields 

per  cent 

1—  6 

7—12 

13—24 

25-36 

0.236 
0.182 
0.150 
0.124 

0.216 
0.160 
0.162 
0.159 

0.220 
0.178 
0.194 
0.134 

0.280 
0.223 
0.197 
0.188 

0.213 
0.156 
0.178 
0.143 

0.233 
0.180 
0.176 
0.150 

-A^verage 
1-36 

0.161 

0.170 

0.176 

0.212 

0.168 

0.177 

2. 

L.A.TE  Wisconsin. 

1—  6 

7—12 

13—24 

25—36 

Average 

1—36 

0.213 
0.178 
0.162 
0.162 

0.173 

0.175 
0.140 
0.147 
0.162 

0.155 

0.207 
0.159 
0.147 
O.UO 

0.147 

0.162 
0.115 
0.131 
0.131 

0.133 

0.213 
0.143 
0.128 
0.137 

0.148 

0.194 
0.147 
0.143 
0.140 

0.151 

CAR£/NGTON  LOAM 

KANSAN  LATE       W  1 5  C  O /^  3  /  N 

I 2_ 3  4  5 


-§■5        /  <?  3  4  3 


CAR2INGT0N        5 1 LT        LOAM 
I £ 3 4.  5 I £ 3 4 6 

iM  ■   ■■  ■    ■      ■    ■    ■""■"IP 

mffffTfT 

r  A  J2  G  O         3  f  LT        LOAM 


t  2  i  4  ^ 


^ffiS 


Fig.  5. — Diagram  slmwing  the  (listrii)utiun  of  phosphoric  acid  on  the  different 
types  on  both  drifts. 


/  a  i  4  5 


PLATE  VI 


-lU  L'fTK^TTlW  VeOET.STION    AND    Toi'OGRAI'H  V    ON    MARSHALL    Sll.T    LOA  M . 

'1.  '  Tioid  V,  a  roadside  strip  remnant  nf  tlie  original  )n-airie. 
2-3.     Fields  I  and  III,  still  in  forest. 
4.     View  of  forest  floor  in  above  fields. 


51 

Marshall  Silt  Loam.  The  i)li<)si)horic  acid  in  soils  from  the  for- 
ested fields,  1,  II  and  III  (Tabic  48)  shows  the  same  irregularity  as 
that  on  tile  other  forest  type,  the  Carrin.q^ton  loam.  The  cleared  fields, 
T\'  and  V,  :.re  in  .i^eneral  more  like  those  on  the  i)rairie  types,  the 
amounts  beiiis;"  considerably  higher  than  those  found  on  the  other 
three,  /.s  pointed  out  above  (p.  24),  the  thickness  of  loessial  deposit 
on  the  three  forested  fields  is  not  great,  the  till  being  encountered  in 
the  third  foct  on  two  of  them  so  that  it  is  not  improbable  that  these 
have  been  souewhat  modified.  The  cleared  fields,  on  the  other  hand, 
appear  to  be  more  typical  of  this  type,  the  thickness  of  the  deposit  here 
being  sulficient  to  remove  any  chance  of  inter-mixing  with  boulder  clay 
from  belDw. 

Table  48. —  FItosplioric  acid  from  the  different  sections  from  the  five  fields  on 
Marshall  silt  loim. 


I'ield 

Field 

Field 

Field 

Field 

Average  for 

Depth 

I 

II 

III 

IV 

V 

5  fields 

Inches 

pt r  cert 

per  cent 

per  cent 

per  cent 

I)er  cent 

per  cent 

1—  6 

(1.167 

0.143 

0.172 

0.226 

0.223 

0.186 

7-12 

(1.153 

0.146 

0.147 

0.207 

0.207 

0.172 

13—24 

(1.124 

0.124 

0.153 

0.162 

0.178 

0.148 

25—36 

0.114 

0.159 

0.153 

0.172 

0.166 

0.153 

A vcrage 
1—36  0.132  0.142  0.155  0.183  0.186  0.160 

Discussion.  The  averages  for  the  five  fields  from  the  diflferent 
types  on  the  two  drifts  are  shown  in  table  49.  The  amounts  found  on 
the  Kansan,  on  each  type  and  in  every  field,  are  greater  than  those  on 
the  Latti  Wisconsin.  The  vertical  distribution  on  the  prairie  types, 
viz.,  the  Canington  silt  loam  and  the  Fargo  silt  loam,  show^s  a  steady 
decrease  from  the  surface  downward  while  that  on  the  forest  types  is 
irregular. 

Tabid  49. — Phosphoric  acid  in  the  different  sections.     The  data  arc  the  aver- 
ages for  the  five  fields  reported  in  tables  43  to  4S  inclusive. 


Marshall 

Depth 
Inches 

Carringl 
Kansan 
per  cent 

on  silt  loam 

Late  Wis. 

per  cent 

Fargo 
Kansan 
per  cent 

silt  loam 
Late  Wis. 
per  cent 

Carringl 
Kansan 
per  cent 

ton   loam 
Late  Wis. 
per  cent 

silt  loam 
Kansan 
per  cent 

1—  6 

7—12 

13—24 

25—36 

0,228 
0204 
0  151 
0.129 

0.182 
0.168 
0.135 
0.113 

0.311 
0.243 
0.186 
0.179 

0.225 
0.184 
0.151 
0.112 

0.233 
0.180 
0.176 
0.150 

0.194 
0.147 
0.143 
0.140 

0.186 

0.172 
0.148 
0.153 

.Vverage 

1—36 

(J.  165 

0.141 

0.214 

0.156 

0.177 

0.151 

0.160 

52 


9.  Potash. 


The  potash  (Table  50)  is  fairly  uniform  for  each  type  on  the  two 
drifts,  the  averages  for  the  three- foot  section,  with  the  exception  of 
those  for  the  Carrington  loam,  being  practically  the  same.  On  the 
T-ate  Wisconsin  the  latter  type  shows  slightly  higher  amounts,  averag- 
ing 1.88  per  cent  compared  with  1.74  on  the  older  drift.  However,  if 
the  amounts  found  in  the  fifteen  fields  on  each  drift  are  averaged  the 
percentage  is  the  same  in  both  cases,  viz.,  1.79. 


Depth 
Inchei- 

1—  6 

7—12 

13—24 

25-36 

Average 

1—36 


Table  30. — Potash  in  the  different  sections. 


Carrington  silt  loam 


Kans 
per  cent 

1.76 
1.84 
1.90 
1.87 


1.86 


Late  Wis. 
per  cent 

1.66 
1.74 
1.86 
1.87 


1.80 


Fargo  silt  loam 
Kansan  Late  Wis 


Carrington  loam 


per  cent 

1.57 
1.64 
1.83 
1.86 


1.76 


per  cent 

1.60 
1.68 
1.71 
1.75 


1.70 


Kansan 
per  cent 

1.72 
1.76 
1.82 
1.65 


1.74 


Late  Wis. 
per  cent 

1.8<^ 
1.9/ 
1.06 
1.76 


l.i 


The  percentages  found  for  the  surface  sections  are,  in  every  case, 
lower  than  those  found  for  the  second,  while  the  amounts  in  the  three 
lower  sections,  except  those  on  the  Carrington  loam,  are  very  similar. 
On  the  type  just  mentioned  the  third  foot-section  carries  on  both  drifts 
a  smaller  amount  than  any  of  those  above  it. 

10.  Soda. 

On  the  two  Carrington  series  the  soda  (Table  51)  is  very  uniform 
for  both  drifts,  showing  little  variation  either  between  the  different 
sections  or  from  the  surface  downward.  With  the  Fargo  silt  loam  the 
amounts  are  distinctly  the  higher  on  the  Kansan,  averaging  1.48  per 
cent  as  compared  with  1.23  per  cent  for  the  younger  drift.  The  widest 
range  in  distnbution  from  the  surface  downward  is  shown  by  the  same 
fields,  where  it  varies  from  1.31  per  cent  in  the  surface  to  1.59  per  cent 
in  the  third  foot. 

Table  ^T. — Soda  in  the  different  sections. 


Depth 
Inches 

1—  6 

7—12 

13—24 

25—36 

Average 

1—36 


Carrington  silt  loam 
Kansan  Late  Wis. 

per  cent  per  cent 


1.26 
1.36 
1.37 
1.20 


1.32 


1.39 
1.35 
1.33 
1.31 


1.33 


Fargo  silt  loam  Carrington  loam 

Kansan  Late  Wis.  Kansan  Late  Wis. 

per  cent  per  cent  per  cent  per  cent 


1.31 
1.48 
1.45 
1.59 


1.48 


1.18 
129 
1.27 
1.18 


1.23 


1.46 
1.42 
1.38 
1.41 


1.41 


1.41 
1.42 
1.40 
1.42 


1.41 


D.  ORGANIC  CONSTITUENTS. 

1.  Volatile  Matter. 

The  volatile  matter,  which  in  the  present  instance  includes  thr 
organic  matter  and  water  of  constitution,  is  reported  in  table  52.  There 
is  very  little  difference  in  the  amounts  found  on  the  two  drifts  when 
the  comparison  is  made  between  the  various  sections  on  the  two  types 
of  the  Carrington  series,  but  a  very  wide  one  is  observ^ed  when  the  sur- 
face 6-inch  section  of  the  Fargo  silt  loam  is  taken  into  consideration. 
On  the  Kansan  this  rises  to  20.34  per  cent  as  compared  with  11.68  ])er 
cent  on  the  Late  Wisconsin. 

Table  52. — J'olatilc  matter  in  the  ditfrrciit  scrtiaiis. 


Depth 
Inches 

1—  6 
7—12 

13—24 
25—36 

Average 

1—36 


Carrington  silt  loam 
Kansan  Late  Wis. 

per  cent  per  cent 

10.52 
8.58 
6.07 
3.73 


l-'argo  silt  loam 
Kansan  Late  Wis. 

lier  cent  i)er  cent 


9.-38 

20.34 

11.68 

7.80 

12.12 

9.61 

5.34 

5.41 

6.43 

2.99 

2.19 

4.40 

Carrington   loam 
Kansan  Late  Wis. 

per  cent  per  cent 


6.45 


5.64 


7.94 


7.16 


6.41 
3.73 
3.32 
2.66 


3.68 


6.71 
4.15 
3.77 
2.89 


4.03 


The  course  of  the  streams  before  the  Late  Wisconsin  glaciation 
was  in  a  general  southwesterly  direction,  but  the  ice.  and  later  the  drift 
material  left  behind,  blocked  the  previously  existing  drainage  channels 
and  forced  the  water  to  find  outlets  to  the  southeast.  Before  these  new 
channels  were  fully  developed  the  drainage  was  verv  incomplete  and 
undoubtedly  large  areas  were  covered  by  standing  water  part  of  the 
season.  The  surface  material  carried  by  the  water  from  the  surround- 
ing highlands  was  thus  deposited  on  the  lowlands.  Organic  material 
accumulated  through  the  growth  of  dense  lowland  vegetation  and  the 
deposition  of  the  remains  of  this.  Little  or  no  peat  was  formed  on  this 
drift. 


On  the  Late  Wisconsin  the  poorly  drained  areas  were  not  as 
numerous  as  on  the  older  formation  and  such  as  existed  were  more  in 
the  form  of  "pot  holes"  in  which  the  conditions  for  the  formation  of 
peat  were  favorable,  so  that  in  most  instances  we  have  the  Fargo  silt 
loam  as  a  narrow  band  between  the  low  lying  peat  areas  and  the  upland 
soil.  Further,  the  high  land  did  not  have  the  black  surface  soil  which 
remained  on  the  unglaciated  Kansan  from  the  as  yet  unnamed  inter- 
glacial  interval  preceding  the  Late  Wisconsin,  and  hence,  the  eroded 
material  accumulated  in  the  lower  lying  areas  was  not  so  rich  in 
oreanic  matter. 


54 

2.     Organic  Carbon. 

The  organic  carbon  was  determined  by  combustion  with  copper 
oxide  in  a  current  of  oxygen,  the  sample  of  soil  having  first  been 
digested  with  phosphoric  acid  solution  and  evaporated  to  dryness. 

The  amounts  of  organic  carbon  (Table  53)  on  both  types  of  the 
series  differ  little  from  drift  to  drift.  The  Carrington  loam  carries 
much  less  than  the  silt  loam.  The  Marshall  silt  loam  closely  resembles 
the  former. 

Tabic  jS. — Organic  Curbon  in  the  different  scctio)is. 

Carrington  silt  loam        Fargo  silt  loam  Carrington  loam       Marshall 

Depth  Kansan     Late  Wis.    Kansan     Late  Wis.    Kansan     Late  Wis.    silt  loam 

Inches  per  cent     per  cent      per  cent      per  cent     jier  cent     per  cent      per  cent 

1—6   4.76  4.48  9.47  5.71  2.83  3.06  2.83 

7—12  3.77  3.19  5.38  3.91  1.34  1.46  1.91 

13—24   1.83  1.78  1.66  2.10  0.79  0.81  1.00 

25—36   0.75  0.77  0.62  1.00  0.50  0.50  0.60 

Average 

1—36   2.28  2.29  3.23  2.64  1.12  1.19  1.32 

With  the  Fargo  silt  loam  the  upper  two  sections  are  much  richer 
in  organic  carbon  on  the  Kansan  than  on  the  Late  Wisconsin.  This 
is  to  be  attributed  to  the  Late  Wisconsin  glaciation  obstructing  the 
drainage  on  the  Kansan  with  resulting  increased  accumulation  of 
eroded  surface  soil  developed  during  pre-Wisconsin  time.  The 
organic  carbon  in  the  second  and  third  foot  sections  on  this  type  shows 
much  less  difference,  it  being  slightlv  the  higher  on  the  I^ate  Wisconsin. 


3.  Nitrogen. 

Nitrogen  was  determined  on  both  sets  of  samples  from  each  field, 
using  the  Gunning  modification  of  the  Kjeldahl  method.  The  normal 
variation  in  upland  fields  shows  a  decrease  from  the  surface  downward, 
this  being  especially  regular  in  the  case  of  prairie  fields  (2,  p.  219). 

Carrington  Silt  Loam.  Considerable  variation  within  the  same 
field  and  from  field  to  field  is  shown  on  both  drifts  (Table  54).  The 
average  amounts  on  the  two  drifts  are  very  similar. 

It  is  to  be  observed  that  in  the  second  and  third  foot-sections  the 
dift"erences  between  the  two  sets  from  the  same  field  and  between  the 
field  samples  are  as  great  as,  if  not  greater  than,  in  the  sections  of  the 
surface  foot  where  a  difference  in  compactness  and  accordingly  a  dif- 
ference in  density  (2,  p.  219)  might  account  for  it. 

Fargo  Silt  Loam.  As  with  the  Carrington  silt  loam,  the  nitrogen 
varies  considerably  from  field  to  field  and  within  a  few  of  the  individual 
fields  (Table  55).  An  extraordinary  range  is  shown  in  Field  IV  on  the 
Kansan,  where  it  varies  from  slightly  over  1.0  per  cent  in  the  surface 
to  .028  per  cent  in  the  subsoil. 


55 


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56 


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Pig.  6.— Diagram  showing  the  distrihtitidii  of  nitrogen  on  tlie  (Hfferent  types 
on  hoth  drifts. 


57  » 

There  is  a  wide  difference  in  the  amounts  of  nitroj^eii  found  in  the 
surface  foot  on  the  two  drifts,  those  on  the  Kansan  heintj',  on  the  aver- 
age, 76  per  cent  the  higher  in  the  surface  six  inches  and  32  per  cent  the 
higher  in  the  second  section.  The  conditions  mentioned  ahove  (p.  53) 
under  which  the  soils  of  this  type  were  developed  furnish  an  explana- 
tion for  this  difference,  the  accumulation  of  organic  matter  and  nitro- 
gen heing  parallel. 

The  average  amount  of  nitrogen  found  in  the  second  and  third 
foot-sections  on  the  two  drifts  are,  on  the  other  hand.  (|uite  similar. 

Carringtoti  Loam.  The  amounts  of  nitrogen  found  in  a  forest  type 
are  naturally  not  as  high  as  those  found  on  the  prairie  types.  The 
variation  (Table  56)  within  the  same  field  and  from  field  to  field,  as 
well  as  the  distribution  from  the  surface  downward,  are  much  the  same. 
There  is  little  dift'erence  between  the  averages  for  the  two  drifts. 

Marshall  Silt  Loam.  The  three  forested  fields,  I,  II  and  Til.  show 
little  variation  within  the  same  field,  but  a  wider  one  from  field  to  field 
(Table  57).  In  the  amounts  present  these  resemble  the  fields  on  the 
Carrington  loam,  a  forest  type. 

The  cleared  fields,  IV  and  V,  resemble  the  ])rairie  types  in  both 
the  amounts  of  nitrogen  and  its  distiHbution. 

Discussion.  The  averages  for  the  five  fields  on  the  different  types 
are  shown  in  tal)le  58.  Both  the  Carrington  silt  loam  and  the  Carring- 
ton loam  are  very  similar  on  the  two  drifts.  The  latter  shows  the 
lowest  percentage  of  all  four  types,  but  this  is  to  be  explained  by  the 
fact  that  the  areas  sampled  were  all  forested  while  prairie  conditions 
prevailed  on  the  other  types,  with  the  exception  of  three  fields  on  the 
Marshall  silt  loam. 

Tabic  38.— Nitrogen  in  the  different  sections.     The  data  arc  averages  for  the 
five  fields  reported  in  tables  54  to  57  inclusi7'c. 

Carrington  silt  loam       Fargo  silt  loam  Carrington  loam       Marshall 

Depth  Kansan     I.ate  Wis.    Kansan     Late  Wis.    Kansan      Late  Wis.    silt  loam 

Inches  per  cent     per  cent       per  cent      per  cent     per  cent     per  cent       per  cent 

1—6       383  .364  .786  .445  .243  .263  .254 

7—12                            .292  .278  .466  .305  .122  .117  .173 

13_'?4   ■■                        166  .164  .152  .\4S  .072  .084  .109 

25—36 .058  .066  .044  .065  .039  .044  .057 

\veraffe 

1-36   187  .184  .274  .196  .0^)8  .106  .126 

With  the  Fargo  silt  loam  the  two  upper  sections  are  much  richer 
in  nitrogen  on  the  Kansan  than  on  the  T-ate  Wisconsin,  the  fomier 
being  76  per  cent  higher  in  the  first  6-inch  section  and  52  ])er  cent  in 
the  second.  This  corresponds  to  the  organic  carbon  (Table  53).  The 
averages  for  the  second  and  third  foot-sections  f.n  this  type  are  very 
similar. 

The  average  for  the  three  feet  on  the  Marshall  silt  loam  is  quite 
similar  to  both  of  those  on  the  Carrington  loam,  the  difference  being 
due  to  the  relatively  large  amounts  found  in  the  two  cleared  fields  on 
the  former. 


58 

E.  COLOR. 

A  color  coni])arison  was  made  of  all  the  samples,  incki<lin£^  those 
of  both  sets  from  each  field.  For  this  purpose  a  25-i^ram  portion  of 
each  soil  passed  through  a  2mm.  sieve,  was  placed  in  a  porcelain  dish 
of  100  cc.  capacity,  moistened  and  allowed  to  temper  for  an  hour. 
Then  all  the  moistened  samples  were  arranged  in  order  of  color,  the 
darkest  being  placed  at  one  end  and  the  lightest  colored  at  the  other. 

It  was  found  possible  to  differentiate  the  soils  into  eight  groups 
(Tables  59  to  62),  the  shades  of  color  in  which  were  fairly  distinct. 
The  graduation  from  one  group  into  another,  however,  was  not  abrupt, 
nor  did  every  member  of  any  of  the  groups  possess  exactly  the  same 
shade  as  all  the  others.  While  eight  shades  of  color  were  distinguish- 
able, there  were  only  three  basic  colors,  viz.,  black,  white  and  red. 
The  members  of  group  1,  the  darkest,  and  of  grou])  2  were  black  to 
black  with  a  brownish  tint,  those  of  group  3  brownish  black  to  dark 
brown,  of  4  dark  brown,  of  5  dark  reddish  brown,  of  6  light  reddish 
brown,  of  7  brownish  red,  and  of  8  brownish  gray  to  light  trray.  The 
color  subsoils,  as  has  recently  been  pointed  out  (1,  p.  253).  is  not 
dependent  upon  the  amount  of  organic  matter,  being  due  in  large 
part  to  other  coloring  material.  The  degree  of  oxidation  of  the  iron 
affects  the  color  as  illustrated  by  groups  7  and  8,  which  have  relativeh' 
the  same  intensity  of  color  but  the  former  has  the  more  pronounced 
reddish  shade  because  of  a  higher  degree  of  oxidation  of  the  iron. 

Carrington  Silt  Loam.  Considerable  variation  in  color  was  found 
between  sets  within  the  same  field  as  well  as  from  field  to  field,  this 
being  as  great  on  one  drift  as  on  the  other  (Table  59). 

On  the  Late  Wisconsin  the  soils  in  the  first  6-inch  section  have, 
in  general,  a  relatively  darker  color  than  those  of  the  corresponding- 
level  on  the  older  formation.  There  is  qtiite  a  marked  difference  in 
the  shade  of  color  between  the  soils  from  the  third  foot  level  on  the 
two  drifts,  those  on  the  Kansan  having  a  distinctly  reddish  tint,  while 
on  the  younger  drift  browns,  grays,  and  grayish  browns  predominate. 
This  would  indicate  that  the  oxidation  of  the  iron  has  not  proceeded 
as  far  on  the  latter.  The  averages  for  the  five  fields,  with  the  excep- 
tion of  the  first  six  inches,  are  the  same. 

Fargo  Silt  Loam.  With  the  exception  of  Fields  I  and  II  on  the 
Late  Wisconsin,  there  is  little  variation  between  the  two  sets  within 
the  same  field  (Table  60).  The  average  for  the  three  foot  sections 
on  the  Kansan  are  the  same,  while  a  wider  variation  is  shown  on  the 
Late  Wisconsin.     On  the  latter  the  color  of   tlie  soils  in  the  second 


59 


■^irvjrovO        -^        —  C-iroO        -^ 


'-  —  <■'■,  OC  -t  ^  — .  fV)  -t  fVl 


—  — '  ^o  t^      -T      n  Csi  T  vc      -t 


—  —  "-,  X        -T        —  — '^1-1-        "Vl 


<0       13  *j 


—  — Tvjt^        <^        (^irviiooo        lO  --      2t!^i  •—  —  '■IOC        T        ,— —  —  CO        1^1 


--^  •— '  ^O  t^        rif        (N)  ^- ro  lO        fO 


.i!'-        —  —  I 


—  —  "^t  -T  '^l 


">j  f\j  ir>  r^        LT)        r—  n  "-^  ir. 


—  —  '■';  oc      -r       — "  —  <^)  -r       '- 1 


<M  IVJ  u-j  t^         LO         —  (M  ^  1  r,         t- 


-r       —  »-•  (M  -r       '^1 


■y.  '■^I  <V1  Tf  t^  -rt  „  ^^  fvj  LO 


—  —  ^'■,00  T  — '-<<N-f  ^1 


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—  ^)T»-  vC 


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<o 


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-1 

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—  — <  C^J  c        ^ 


^      .— * 


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—  r^  -^  n  ^  -' 


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60 

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61 

and  third  foot-seclions  is  relatively  darker.  With  this  type  the  grays 
characterize  the  third  foot-sections  on  the  Kansan,  heing^  absent  from 
a  majority  of  the  fields  on  the  Late  Wisconsin,  a  condition  just  the 
opposite  to  what  prevailed  on  the  Carrinyton  silt  loam.  This  may  be 
attributed  to  the  obstructed  drainati^e,  mentioned  above,  on  the  older 
drift,  the  water  table  beinij  relatively  close  to  the  surface,  this  exclud- 
ing the  air  and  preventing  any  considerable  oxidation  of  the  iron 
compounds,  while  on  the  younger  formation  this  type  is  confined  to 
more  or  less  narrow^  bands  around  the  lower  lying  areas  and  conse- 
quently does  not  have  the  water  table  as  near  to  the  surface. 

Carrington  Loam.  The  remarkable  similarity  between  the  two 
drifts  characteristic  of  the  soils  of  this  type  already  mentioned  extends 
to  the  color  also  (Table  61).  With  the  exception  of  Field  I  on  the 
Kansan,  there  is  little  variation  within  the  individual  fields,  either 
from  field  to  field,  or  from  drift  to  drift. 

Marshall  Silt  Loam.  There  is  little  variation  in  color  between 
the  soils  from  the  two  sets  within  the  same  field  (Table  62)  but,  as 
with  the  chemical  composition,  there  is  a  marked  difference  between 
the  three  forested  fields,  T,  II  and  III,  and  the  two  cleared  ones,  IV 
and  V.  On  the  latter  the  effect  of  the  accumulation  of  organic  matter 
has  reached  as  far  as  the  third  foot,  causing  a  darker  shade  than  if 
found  in  the  corresponding  level  in  the  forested  fields. 

Discussion.  The  averages  for  the  five  fields  on  the  different  types 
on  the  two  drifts  are  shown  in  Table  63.  There  is  little  difference 
in  intensity  of  color  between  the  soils  of  any  one  type  on  either  drift, 
and  none  at  all.  if  we  except  the  surface  6  inches,  on  the  Carrington 
silt  loam  and  the  second  and  third  foot-sections  on  the  Fargo  silt 
loam.  In  the  case  of  these  exceptions  the  color  of  the  soils  on  the 
Late  Wisconsin  is  darker,  indicating  a  condition  just  opposite  to 
that  reported  by  Burke  and  Kolbe  (11,  p.  21),  who  presumably  refer 
to  the  surface  soil  when  they  state  that  "the  Kansan  drift  has  generally 
a  darker  color  than  the  Wisconsin." 

Table  63. — Relative  shade  of  color.  The  data  are  the  averages  for  the  fire 
fields  reported  in  tables  59  to  62  inclusive. 

Depth  Carrington  siH  loam  Fargo  silt  loam  Carrington  loam  Marshall  silt 

Inches  Kansan      Late  Wis.     Kansan       I.ate  Wis.     Kansan     I. ate  Wis.         loam 

1—6    2  1  1  1  3  ?,  ;, 

7—12    2  2  1  1  4  4  5 

13—24    3  3  3  2  6  6  6 

25—36    6  6  8  4  7  7  6 

Average 

1—36    4  4  4  2  5  5  5 


62 

CLASSIFICATION  OF  RICE  COUNTY  TYPES  ACCORDING 
TO  THE  RUSSIAN  SYSTEM. 

Having  reported  in  detail  the  composition  and  properties  of  three 
soil  types,  it  will  be  of  interest  to  consider  their  classification  according 
to  the  Russian  system.  The  present  and  past  climate  of  Minnesota 
excludes  the  probability  of  any  of  these  belonging  to  either  Class  I 
(  Laterites  and  Red  Earths)  or  Class  IV  (Semi-arid  and  Arid  Soils). 
Class  V  (Soils  formed  under  an  excess  of  moisture)  are  represented 
only  by  the  peat  areas,  which  are  not  included  in  the  present  study, 
and  Class  \'I  (Alkali  Soils),  so  far  as  now  known,  are  entirely  absent. 
This  leaves  the  three  types  studied  to  be  assigned  to  either  of  the  two 
remaining  classes,  or  partly  to  each,  viz.,  Class  IH  (Chernozem  or  Ijlack 
Prairie  Soils)  and  Class  H  (Podzols,  Gray  Forest  Soils,  Brown 
Earths  and  De^jraded  Chernozem). 

The  soils  of  Class  HI,  true  chernozems,  are  characterized  in  the 
surface  layer  by  a  content  of  organic  carbon  from  3.5  to  6.0  per  cent 
and  of  nitrogen  from  0.30  to  0.50  per  cent  (21,  p.  318),  and  a  neutral 
reaction  while  the  soil  just  below  the  dark  colored  portion  efifervesces 
with  dilute  acids.  The  data  in  Table  64  illustrates  the  character  of 
typical  Russian  chernozems  (21,  p.  318).  The  soils  of  Class  II, 
degraded  chernozems,  podzols  and  Brown  Earths,  are  lower  in  organic 
carbon  and  nitrogen  and  are  characterized  by  an  acid  reaction  (16. 
p.  88)  of  the  surface  layer. 

Table  64. — Organic  Constituents  in   the  surface  foot   (approx.)   of  Russian 
cltcrnosein  according  to  Kossorvitsch. 

Organic  V^olatile         Organic  Carbon 

matter  matter  carbon*        Nitrogen         dioxide 

Source  of  sample  per  cent  per  cent         per  cent  per  cent       per  cent 

Orel,  Mzensk  Maloarchang....  11.37  13.20  6.59  0.51 

Woronesh.  Bobrowsk    11.73  14.67  6.80  0.55  0.00 

Ufa,   Belebeiew    16  72  19.56  9.69  0.83  2.23 

Tobolisk,  Tjukalinsk   10.82  14.22  6.27  0.48  0.00 

•Organic  Matter  -H   1.724. 

Of  the  Rice  county  soils  (Table  65)  the  Fargo  silt  loam  is  clearly 
a  true  chernozem,  the  organic  carbon  and  nitrogen  falling  well  above 
the  lower  limits  of  the  amounts  of  these  constituents  found  in  the 
chernozems  of  Russia.  The  Carrington  silt  loam  also  would  be  placed 
in  this  class  if  we  considered  only  the  proportions  of  organic  carbon 
and  nitrogen  but,  considering  also  the  acid  reaction  of  the  surface 
layer  and  the  non-calcereous  nature  of  the  subsoil  immediately  below 
this,  we  must  regard  it  as  being  in  the  early  stages  of  degradation. 
Table  65. — Organic  Constituents  in  the  surface  foot  of  Rice  County  soils. 
The  data  are  averages  of  the  two  corresponding  drift  samples. 

Volatile  Organic  Carbon 

Matter  Carbon        Nitrogen     Dioxide 

per  cent  per  cent        per  cent      per  cent  Keaction 

Fai-Ko  Silt  Loam 13.44  6.12  .50  .390  v.  si. 

Carrington  Silt  Loam  9.07  4.29  .33  .076  med. 

Carrington  Loam 5.25  2.25  .19  .077  med. 

Marshall  Silt  Loam 2.37  .21  ....  med. 

With  the  Carrington  loam  this  process  has  advanced  still  further, 
placing  the  type  clearly  outside  of  the  chernozems.  The  lower  con- 
tent of  organic  carbon  and  nitrogen  and  the  acid  reaction  of  the  whole 
three  foot-section  shows  that  it  belongs  in  Class  II,  and  since  it  both 
lacks  the  characteristic  podzol  horizon  (16,  p.  68),  and  compared  with 
the  Gray  Forest  Soils  has  a  relatively  high  content  of  organic  matter, 
it  is  to  be  considered  as  degraded  chernozem. 


SUMMARY. 


The  thesis  icpuris  a  study  of  the  relation  of  the  chemical  com- 
position and  the  physical  properties  of  certain  glacial  soils  of  Minne- 
sota to  the  age  of  the  drift  upon  which  they  have  heen  developed. 
The  Helds  sampled  are  in  Rice  county,  for  which  detailed  glacial  and 
soil  surveys  were  available.  This  county  is  covered  in  ])art  by  the 
latest  drift,  the  l^te  Wisconsin,  and  the  remainder  by  the  earliest 
exposed  in  Minnesota,  the  Kansan,  both  derived  from  [)ractically  the 
same  sources  and  both  originally  highly  calcareous  from  the  surface 
downward  while  the  southern  tip  of  the  deciduous  forest,  the  Big 
Woods  of  Minnesota,  extended  down  into  it  from  the  north  and  occu- 
pied extensive  areas  on  both  sides  of  the  dividing  line  between  the 
two  drift  sheets. 

On  each  of  three  types,  the  loam  and  the  silt  loam  of  the  Carring- 
ton  series  and  the  silt  loam  of  the  Fargo  series,  representing,  resp(;c- 
tively,  forest,  upland  grassland  and  lowland  grassland,  ten  virgin 
fields  were  sampled,  five  on  the  Late  Wisconsin  and  five  on  the  Kansan. 

All  the  fields  sampled  for  the  Carrington  series  were  so  situated 
as  to  h.ave  been  fully  exposed  to  the  leaching  effect  of  the  portion  of 
the  precipitation  passing  from  the  surface  into  the  deeper  subsoil. 
The  Fargo  silt  loam  had  developed  under  such  poor  natural  drainage 
conditions  that  on  many  of  the  fields  of  this  ty])e  there  was  little  or 
no  leaching  to  be  expected. 

The  samples  were  taken  to  a  depth  of  three  feet  in  four  separate 
sections,  the  first  six  inches,  the  second  six  inches,  the  second  foot, 
and  the  third  foot.  In  each  field  two  sets  were  taken,  these  being- 
composites  from  ten  borings,  and  these  two  sets  were  combined  to 
form  the  field  samples.  Complete  analyses  were  made  of  the  com- 
posites of  the  corresponding  sections  from  the  five  fields  on  the  same 
type  and  the  same  drift,  determinations  of  the  phosphoric  acid  and 
carbon  dioxide  of  all  the  field  samples,  and  of  the  moisture  equivalent, 
proportions  of  coarser  rock  fragments,  nitrogen,  color  and  reaction 
by  various  methods  of  all  the  set  samples. 

Five  fields  on  a  fourth  soil  type,  Marshall  silt  loam,  developed 
only  upon  the  loess  overlying  the  Kansan  till,  were  included  in  the 
study  and  treated  similarly  insofar  as  part  of  the  determinations  are 
concerned.  Three  of  these  were  still  in  virgin  forest,  and  two  were 
adjacent  to  land  that  had  been  cleared  and  given  over  to  farming. 

The  texture  of  the  fine  earth  of  each  type,  as  indicated  by  the 
moisture  equivalent,  is  very  similar  on  both  drifts,  but  the  proportion 
of  coarser  fragments  is  lower  in  the  soils  on  the  Kansan  than  in  those 
on  the  Late  Wisconsin.  On  the  older  formation,  the  original  frag- 
ments of  the  softer  rock  (limestones,  shales,  and  cherts),  have  almost 
entirely  given  way  to  the  processes  of  weathering  throughout  a  depth 
greater  than  three  feet. 


64 

A  general  relation  was  found  to  exist  between  the  calcereousnes.s 
and  the  texture,  the-  finest  txtured  soils  retaining  the  most  carbonate 
and  the  coarsest  the  least. 

With  the  two  members  of  the  Carrington  series  the  degree  of 
acidity,  as  indicated  by  three  different  methods,  the  litmus,  the  Truog 
and  the  ammonia,  is  the  more  pronounced  on  the  Kansan.  With  the 
loam  the  carbon  dioxide  content  is  alike  on  both  drifts,  carbonates 
having  been  removed  to  a  depth  in  excess  of  three  feet,  but  with  the 
silt  loam,  while  on  the  Kansan  the  leaching  has  been  as  extensive  as 
on  the  preceding  type,  considerable  amounts  of  carbonate  still  remain 
in  the  third  foot  on  the  Late  Wisconsin.  On  the  fields  of  the  Fargo 
type  much  less  carbonate  has  been  removed  in  the  case  of  either  drift 
and  the  reaction  is  less  frequently  acid  on  the  Kansan  than  on  the 
younger  drift. 

On  the  Kansan  the  calcium  carbonate  has  been  leached  out  to 
a  depth  greater  than  three  feet  on  both  the  Carrington  types,  while 
on  the  Late  Wisconsin  the  same  is  true  for  the  Carrington  loam  but 
there  is  still  an  appreciable  quantity  in  the  third  foot-section  of  the 
Carrington  silt  loam. 

The  lime  other  than  that  in  the  form  of  carbonate  is  similar  both 
in  amount  and  distribution  on  the  two  Carrington  types,  but  in  the 
first  two  feet  in  the  Fargo  silt  loam  is  considerably  the  higher  on  the 
ICansan. 

The  magnesia  on  each  type  is  very  similar  from  drift  to  drift, 
but  is  considerably  higher  in  the  l^^argo  silt  loam  than  in  the  other 
types. 

The  ratio  of  total  lime  to  magnesia  is  slightly  the  higher  on  the 
Late  Wisconsin,  this  being  due  to  the  greater  amount  of  calcium 
carbonate  on  the  two  of  the  types  on  the  latter.  The  ratio  of  lime,  in 
the  form  of  silicate,  to  magnesia  is  very  similar  for  each  type  from 
drift  to  drift,  except  with  the  Fargo  silt  loam  where  it  is  the  lower  on 
the  younger  formation. 

The  phosphoric  acid  is  the  higher  on  the  Kansan,  this  being  true 
for  each  of  the  three  types.  The  amounts  were  determined  in  all  ten 
fields  on  each  type  and  with  every  type  the  individual  fields  on  the 
Kansan  showed  an  amount  higher  than  or  practically  equal  to  that 
in  the  field  on  the  Late  Wisconsin  richest  in  this  constituent.  On  the 
two -prairie  types  it  shows  a  decrease  from  the  surface  downward,  but 
with  the  forest  type  the  vertical  distribution  is  irregular. 

Both  potash  and  soda  are  very  similar  in  corresponding  sections 
from  the  two  drifts  except  that  with  the  Carrington  loam  the  potash 
is  slightly  the  higher  and  the  soda  distinctly  the  lower  on  the  later 
glaciation. 

In  volatile  matter  the  corresponding  sections  from  the  two  drifts 
are  very  similar  except  that  the  Fargo  silt  loam  in  the  surface  six-inch 


65 


section   shows   nearl)    twice  as   niiicli   on   the    Kaii>an   as  oil    the    Late 
Wisconsin. 

The  organic  carhon,  huth  in  anionnt  anil  (hstrihntion,  is  very 
similar  from  drift  to  drift  with  both  of  the  Carrinj^^ton  types,  hut  in 
the  first  two  sections  of  the  Fars^o  sih  loam  it  is  the  higher  on  the 
Kansan,  in  this  resembling  the  volatile  matter.  The  forested  fields 
show  lower  percentages  than  those  on  the  grassland. 

The  distribution  of  nitrogen  resembles  that  of  organ.ic  carbon 
and  volatile  matter. 

In  relative  darkness  of  color  there  is  no  difference  between  the 
drifts  in  the  case  of  any  of  the  soil  types,  except  in  the  surface  six-inch 
section  on  the  Carrington  loam  and  the  second  and  third  foot-sections 
on  the  Fargo  silt  loam.  \\\\h  these  the  soil  on  the  T.ate  W^isconsin  is 
somewhat  the  darker. 

If  the  three  types  of  soils  studied  in  detail  were  to  be  classified 
according  to  the  Russian  system,  the  Fargo  silt  loam  would  be  con- 
sidered a  true  chernozem,  the  Carrington  silt  loam  a  chernozem  in 
the  early  stages  of  degradation,  and  the  Carrington  loam  a  degraded 
chernozem. 

In  general,  the  first  three  feet  of  soil  on  the  well-drained  areas, 
originally  similar  in  topography  and  profile  and  later  covered  by  the 
same  type  of  vegetation,  are  almost  identical  on  the  two  drifts,  which 
would  suggest  that  the  age  of  the  most  recent  glaciation  is  so  great  as 
to  have  permitted  the  uniformity  in  climate  and  in  vegetative  cover, 
which  has  prevailed  on  the  two  sides  of  the  dividing  line  in  any 
locality,  to  almost  completely  obliterate  the  effects  of  the  great  differ- 
ence in  age. 

It  appears  probable  that  the  previously  reported  marked  differ- 
ences in  composition  between  the  soils  on  the  Kansan  and  on  the  Des 
Moines  Lobe  of  the  Late  Wisconsin  are  to  be  attributed  to  the  effects 
of  the  differences  in  climate  and  vegetation  that  are  involved  when 
we  employ  data  from  large  sections  extending  far  to  the  east  and  to 
the  west,  respectively,  of  the  contact  line  of  the  surface  ex|)osures  of 
the  two  glacial  sheets.  It  is  prol^able  that  the  diff'erences  which  have 
been  induced  by  differences  in  precipitation  and  vegetation  within  the 
area  of  any  one  glaciation  may  be  found  to  far  exceed  those  attribut- 
able onlv  to  diff'erences  in  the  age  of  glaciation. 


66 


LITERATURE   CITED. 


(1)  Alway,  F.  J.,  and  Blish,  M.  J. 

1916.  The  loess  soils  of  the  Nebraska  portion  of  the  transition  region: 
IT.  Humus,  humus-nitrogen  and  color.  Jn  Soil  Sci.  v.  i,  no.  3, 
p.  239-238,  4  fig. 

(2)  Alway,  F.  J.,  and  McDole,  G.  R. 

1916.  The  loess  soils  of  the  Nebraska  portion  of  the  transition  region: 
I.  Hygroscopicity,  nitrogen,  and  organic  carbon.  lu  Soil  Sci.. 
1'.  I,  no.  3,  p.  197-238.  2  fig;  3  Pl- 

(3)  Alway,  F.  J.,  and  Rost,  C.  O. 

1916.  The  vertical  distribution  of  phosphorus  in  the  surface  soil  of 
prairies.    lit  Soil  Sci.,  v.  2,  no.  5,  p.  493-49/. 

(4)  Alway,  F.  J.,  and  Rost,  CO. 

1916.  The  loess  soils  of  the  Nebraska  portion  of  the  transition  region: 
IV.  Mechanical  composition  and  inorganic  constituents,  hi 
Soil  Sci.,  r.  i,  no.  5,  p.  405-436.  2  fig. 

(5)  Alway.  F.  J.,  and  Russel,  J.  C. 

1916.  Use  of  the  moisture  equivalent  for  the  indirect  determination  of 
the  hygroscopic  coefficient,  fn.  Jour.  Agr.  Research,  v.  6,  no. 
22,  p.'S33-846. 

(6)  Briggs,  L.  J.,  and  McLane.  J.  W. 

1907.  The  moisture  equivalents  of  soils.  U.  S.  Dept.  Agr.  Bur.  Soils 
Bui.  45,  23  p.,  1  fig.,  1  pi. 

(7)  Briggs,  L.  J.,  and  McLane.  J.  W. 

1910.  Moisture    equivalent    determinations    and    their    application.      Jn 

Proc.  Anicr.  Soc.  Agron.,  v.  2,  p.  138-147.  6  pi. 

(8)  Briggs,  L.  J.,  and  Shantz,  H.  L. 

1912.  The  wilting  coefficient  for  different  plants  and  its  indirect  determi- 
nation. U.  S.  Dept.  Agr.  Bur.  Plant  Indus.  Bui.  230,  83  p..  9  f^g.. 
2  pi. 

(9)  Brown,  P.  E. 

1914.     The  fertility  in  Iowa  soils.    Iowa  Agr.  Exp.  Sta.  Bui.  150,  p.  89-152. 

(10)  Buchanan,  H. 

1807.  Tourney  from  Madras  through  Mvsore.  Canara,  and  Malabar. 
Vol.  IJ. 

(11)  Burke.  R.  T.  A.,  and  Kolbe.  L.  A. 

1911.  Soil   survey  of  Rice  County,  Minnesota.     Advance   sheets   from 

field  operations,  1909,  39  p.,  1  fig.,  1  map. 

(12)  Bureau  of  Soils. 

1013.  Soils  of  the  United  States.  U.  S.  Dept.  Agr.  Bur.  Soils  Bui.  96. 
p.  791,  13  fig..  2  pi. 

(13)  Chamberlin,  T.  C,  and  Salisbury,  R.  D. 

1907.     Geology,  vol.  Ill,  624  p.,  576  figs.    Holt  &  Co.,  New  York. 

(14)  DOKUTSCHAJEW,   V.   V. 

1883.     Russian  chermozem.     St.  Petersburg. 


67 

(15)  CiLIKKA,   K. 

1915.     Pedologie.     (Kuss.)     Petrogiad. 

(16)  Glinka,  K. 

1914.  Die  typon  dcr  Bodenbildung.,  358  p.,  65  fig.,  map.    Berlin. 

07)      HiLGAHJ),  E.  W. 

1892.  A  report  (.m  the  relation  of  ^oils  to  climate.  U.  S.  Dept.  Agr. 
Weather  Bur.  Bill.  .V 

(,18)     ]liUi.\Hi),  E.  W. 

1895.  Origin,  value,  and  reclamation  of  alkali  lands.  In  yearbook  of 
U.  S.  I^cpt.  Af^r.,  />.  103. 

(19>       HU.LEBK.VNU,   W.    F. 

l'>10.  The  analysis  of  silicate  and  carbonate  rocks.  U.  S.  Geol.  Survey 
Bui.  422,  239  p.,  27  fig. 

(20)  Hopkins,  C.  G.,  and  Pettit,  J.  H. 

1908.  The  fertility  in  Illinois  soils.  111.  Agr.  Exp.  Sta.  Bui.  123,  p.  187- 
294.  8  pi. 

(21)  KossowiTSCH,  p. 

1912.  Die  Swart/erde  (Tschernosiom ).  //;  Jntentat.  Mitt.  Bodenk, 
Bd.  I.  p.  rgc}-S5i. 

(22)  Leverett,  Fkaxk. 

1910.  Comparison   of   North   .\mcrican  and   European  glacial   deposits. 

In  Zcitschrift  fiir  Glctschcrknndc.    v.  14.  p.  241-316,  j  Hg.,  5  pi. 

{2i)     Leverktt,  Er.v.vk,  and  S.\rdeson,  F.  W. 

1917.  Surface  formations  and  agricultural  conditions  of  northeastern 
Minnesota.     Minnesota  Geological  Survej'  Bui.  13,  p.  72,  15  fig.. 

(24 >     LoEvv.  Osc.\R. 

1901.  The  relation  of  lime  and  magnesia  to  plant  growth.  I.  Liming 
of  soils  from  a  ph3'siological  standpoint.  In  U.  S.  Dept.  Agr. 
Bur.  Plant  Indus.  Bui.  i.  p.  1-35. 

(25)  McMiLLER,  P.  R. 

1915.  A  study  of  the  glacial  and  loessial  soils  of  the  most  southerly  tier 

of  counties  in  Minnesota.     Thesis,  Uniyersity  of  Minnesota. 

(26)  May.  D.  W. 

1901.     The  relation  of  lime  and  magnesia  to  plant  growth.     II.     Experi- 
mental  study  of  the  relation   of    lime  and  magnesia  to  plant 
growth.    In  U.  S.  Dept.  Agr.  Bur.  Plant  Indus.  Bui.  i.  p.  37-53, 
3PI- 
{27)     Rama.nn,  E. 

1911.  Bodenkunde,  ed.  3.  p.  619,  63  fig. 

(28)  RosT,  Clayton  O. 

1917.  The  determination  of  soil  phosphorus.  In  Soil  Sci..  t'.  /,  no.  /,  p. 
^95-311- 

(29)  Smith,  J.  Lawrence. 

1871.  On  the  determination  of  the  alkalies  in  silicates  ignited  with  car- 
bonate of  lime  and  sal  ammoniac.    In  Am.  Jour.  Set.,  2nd  ser., 

vol.  50.  p.  26i). 

(30)  Truog,  E. 

1915.     A  new  test  for  soil  acidity.     Wisconsin  .Agr.  Exp.  Sta.  Bui.  294, 
15  p.,  3  fig.,  1  ch. 

(31)  Warth,  F.  J. 

1903.  The  composition  of  Indian  laterite.  In  Geological  Magazine,  v.  4, 
no.  10,  p.  154-159- 

(32)  Washington,  H.  S. 

1910.    Manual  of  chemical  analysis  of  rocks.     Ed.  2,  200  p.     New  York. 
i^i)     Wheeler.  H.  J.,  Hartwell,  B.  L.,  and  Sargent,  C.  L. 

1899.  Chemical  methods  for  ascertaining  the  lime  requirement  of  soils. 
Rhode  Island  Agr.  Exp.  Sta,  Bui.  62. 


68 

BIOGRAPHICAL  SKETCH. 

Clayton  Ord  Rost  was  born  near  Ord,  Valley  county,  Nebraska, 
on  Nov.  24,  1885.  His  elementary  education  was  secured  in  public 
schools  near  Nebraska  City  and  at  Orchard,  Nebr.,  where  he  com- 
pleted the  ninth  grade.  Later  he  attended  the  Nebraska  Normal 
College  at  Wayne  and  the  Nebraska  State  Normal  College  at  Peru, 
entering  the  University  of  Nebraska  in  1908.  In  1911  he  received 
the  degree  of  Bachelor  of  Science  with  his  major  in  chemistry,  and 
in  1912  the  degree  of  Master  of  Arts  with  his  major  in  agricultural 
chemistry. 

From  November,  1912,  to  August,  1913,  he  was  research  assist- 
ant in  agricultural  chemistry  in  the  Nebraska  Agricultural  Experiment 
Station.  In  August,  1913,  he  was  appointed  assistant  chemist  in  the 
Division  of  Soils  of  the  Agricultural  Experiment  Station,  University 
of  Minnesota.  He  continued  advanced  work  in  the  Graduate  School 
of  the  same  University,  completing  the  residence  and  course  work  for 
the  degree  of  Doctor  of  Philosophy  in  June,  1918. 

Major — Soil  Chemistry. 

Minor — Geology  (petrography) . 

Thesis — Parallelism  of  the  soils  developed  on  the  Gray  Drifts 
of  Minnesota. 

Phi  Beta  Kappa. 

Sigma  Xi. 

Publications. 

The  determination  of  total  manganese  in  soils.  (With  R.  A. 
Gortner.)    In  Jour.  Indus.  Eng.  Chem.  v.  4,  No.  7  (1912),  p.  522-524. 

The  loess  soils  of  the  Nebraska  portion  of  the  transition  region ; 
IV.  Mechanical  composition  and  inorganic  constituents.  (With  F. 
J.  Alway.)     In  Soil  Science,  v.  1,  No.  5  (1916).  p.  405-437,  2  fig. 

The  vertical  distribution  of  phosphorus  in  the  urface  soil  of 
prairies.  (With  F.  ].  Alway.)  In  Soil  Science,  v.  2,  No.  5  (1916), 
p.  493-498. 

The  loess  soils  of  the  Nebraska  portion  of  the  transition  region : 
VI.  The  relative  "rawness"  of  the  subsoils.  (With  F.  J.  Alway  and 
G.  R.  McDole.)  /;;  Soil  Science,  v.  3,  No.  1  (1917)  p.  9-36,  9  plates, 
4  figs. 

The  determination  of  .soil  phosphorus,  in  Soil  Science,  v.  4,  No. 
4  (1917),  p.  295-312. 

Determination  of  lime  and  phosphoric  acid  in  peat  soils :  Com- 
parison of  Jonkoping  with  Bremen  method.  (With  F.  C.  Clap]).) 
In  Soil  Science,  v.  5,  No.  3  ( 1918) ,  p.  213-219. 


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